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Amp Gauge

C

Caryc

Well-known Member
Ok, I found out the hard way that a Ford tractor starter solenoid and a Ford auto solenoid are not the same thing.

So, before I waste any more money let me ask a dumb question. I need to replace the amp gauge on my 8N. Is an amp gauge just an amp gauge? I would seriously think so myself. But when you have all this knowledge at hand, why not ask in advance?

So, can I run down to the auto parts store and pick up an amp gauge?
 
"Ok, I found out the hard way that a Ford tractor starter solenoid and a Ford auto solenoid are not the same thing."

Actually, Ford autos of the same time period as the tractor used the same style of starter solenoid! (The type that needs it's little terminal GROUNDED to activate it.)

As to the ammeter, match the Amp rating of the meter to your charging system... with an original 6-Volt system a 20-0-20 Ammeter will be easier to read/more accurate than the 60-0-60 Ammeter needed with a 12 Volt alternator conversion. If you DO still have a 6 Volt genny it MAY be hard to find a 20-0-20 Ammeter at an auto parts store nowadays!

Up to a certain point, Ford used "induction ammeter" that had a little clip on the back that the wire passed through, rather than the modern shunt ammeters that have the two terminals.

I don't know where your tractor fits into that scheme, but if it DOES have an induction ammeter you can take the charging wire off of the junction block and connect it to one terminal of the ammeter, then make up a jumper to connect the other post of the ammeter back to the junction block.

If the Ammeter reads backwards, swap the leads between the posts.
 

Thanks Bob,

It's 12 volt with an alternator. Amp gauge has two posts on the back, two large red wires with one smaller yellow wire to the key switch. Stock key switch. I still have the big thumb starter button on the trans.

Face reads -30 to +30
 
For what your doing one from the auto parts store will work just fine and an amp gauge does not care if it is 6 or 12 volts. Also as Bob said if you know your charging system is working fine but your gauge shows discharge instead of charge you have the wires on back wards
 
Thanks guys. Finding this forum was the next best thing to finding my tractor.

Just two months ago I was driving into town on a Saturday morning and along the highway there was what looked like an 8N with a for sale sign on it and a guy sitting in a lawn chair.

I planned on stopping on my way home just to see how much he was asking for it and if maybe he had any implements that he might sell separately that I could use on my 8N.

Anyway, just two and half hours later on my way back, him and the tractor were gone. I had been to town the previous day so I knew that tractor was not there then. So that tractor went in maybe three hours. That's how hard they are to find around here. I only got mine because a neighbor down the road from me was moving out of the state.
 
Ok, guys I went down and got a Stewart Warner Amp guage. -30 to +30, same as the old one. I hooked the three wires on the new one same as the old one. One larger gauge red wire from the plus side of the gauge down to the starter solenoid.

The negative side post has one larger gauge red wire running from the gauge to the back of the alternator. This same post has a smaller gauge yellow wire running from the gauge to one side of the key switch.

So my question is why doesn't the new gauge work? Dummy alert here. I really don't remember if the old gauge ever worked or not. I did replace the tach that was not working when I got the tractor.

I didn't try reversing any of the wires because it is starting to rain outside, but like I said it's wired the same as the old gauge.

It would not hurt anything if I switched the two big red wires on the gauge would it? And how about the little yellow wire going to the key switch? Is it ok to switch that one also? I just don't want to burn anything up here.

Now I'm bummed.....$24 smackers for a gauge and it doesn't work. I'm tired of buying parts that don't work.
 
(quoted from post at 22:38:29 03/06/10) Ok, guys I went down and got a Stewart Warner Amp guage. -30 to +30, same as the old one. I hooked the three wires on the new one same as the old one. One larger gauge red wire from the plus side of the gauge down to the starter solenoid.

The negative side post has one larger gauge red wire running from the gauge to the back of the alternator. This same post has a smaller gauge yellow wire running from the gauge to one side of the key switch.

So my question is why doesn't the new gauge work? Dummy alert here. I really don't remember if the old gauge ever worked or not. I did replace the tach that was not working when I got the tractor.

I didn't try reversing any of the wires because it is starting to rain outside, but like I said it's wired the same as the old gauge.

It would not hurt anything if I switched the two big red wires on the gauge would it? And how about the little yellow wire going to the key switch? Is it ok to switch that one also? I just don't want to burn anything up here.

Now I'm bummed.....$24 smackers for a gauge and it doesn't work. I'm tired of buying parts that don't work.
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You should have got a volt meter and did away with the amp meter...

WARNING :shock: all I know I read on the Internet,,, do it enuff and you can become a guru also,,, not responsible for damages,,, I read it and just pass it along,,, proceed with caution
 
(quoted from post at 17:38:29 03/06/10) Ok, guys I went down and got a Stewart Warner Amp guage. -30 to +30, same as the old one. I hooked the three wires on the new one same as the old one. One larger gauge red wire from the plus side of the gauge down to the starter solenoid.

The negative side post has one larger gauge red wire running from the gauge to the back of the alternator. This same post has a smaller gauge yellow wire running from the gauge to one side of the key switch.

So my question is why doesn't the new gauge work? Dummy alert here. I really don't remember if the old gauge ever worked or not. I did replace the tach that was not working when I got the tractor.

I didn't try reversing any of the wires because it is starting to rain outside, but like I said it's wired the same as the old gauge.

It would not hurt anything if I switched the two big red wires on the gauge would it? And how about the little yellow wire going to the key switch? Is it ok to switch that one also? I just don't want to burn anything up here.

Now I'm bummed.....$24 smackers for a gauge and it doesn't work. I'm tired of buying parts that don't work.
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ew gauge is probably wired wrong as was the old one. Compare your wiring to correct diagrams & see what is different.
 
Where can I find these "correct diagrams"? In all of the repro manuals I have it just shows a wiring harness. No color coding and I can't tell what is hooked to what. When a wire goes into the harness I have no way of knowing which one it is coming out of the harness.

I guess I'll just have to count my blessings that the thing is running and not press my luck. I don't want to burn anything out and have more problems.
 
(quoted from post at 22:14:00 03/06/10) When a wire goes into the harness I have no way of knowing which one it is coming out of the harness..
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It SHOULD not change color in the middle.

It should be the same color on both ends.

Heck, I think I will hush, I made my own out of all the same color wire, before I found this forum, or ever seen a diagram.

I think JMOR has a color coded diagram.
 
(quoted from post at 19:19:12 03/06/10)
(quoted from post at 22:14:00 03/06/10) When a wire goes into the harness I have no way of knowing which one it is coming out of the harness..
Click to expand...

It SHOULD not change color in the middle.

It should be the same color on both ends.

Heck, I think I will hush, I made my own out of all the same color wire, before I found this forum, or ever seen a diagram.

I think JMOR has a color coded diagram.
Click to expand...

If you read my post again, you will see that I said the picture of the wiring harness was in black and white, no color coding. That's why I can't tell if a wiring going into the harness is which wire coming out at the other end.
 
Well, I switched the three wires on the two terminals of the amp gauge and still nothing. :cry:

Surely a simple amp gauge can't be so complicated?

At least I have a neighbor down the road with an 8N. When it stops raining, maybe I'll go take a look at his amp gauge.
 
(quoted from post at 16:52:35 03/07/10) Well, I switched the three wires on the two terminals of the amp gauge and still nothing. :cry:

Surely a simple amp gauge can't be so complicated?

At least I have a neighbor down the road with an 8N. When it stops raining, maybe I'll go take a look at his amp gauge.
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One post on ammeter should receive power from battery (usually a connection from the solenoid or starter switch...same post as battery cable).
Everything else to other ammeter post. That's all.
 
Here's a pic. Prior to me switching, the two wires on the inside post were on the outside post. So, am I correct in assuming the the ceramic looking thing is the junction box mentioned in wiring diagrams? By the way, that little yellow wire runs to the outside post on the key switch.

The red wire with the tape flag on it runs down to the starter solenoid. The other red one runs to the back of the alternator.

F-JunctionBox.jpg
 
(quoted from post at 17:28:49 03/07/10) Here's a pic. Prior to me switching, the two wires on the inside post were on the outside post. So, am I correct in assuming the the ceramic looking thing is the junction box mentioned in wiring diagrams? By the way, that little yellow wire runs to the outside post on the key switch.

The red wire with the tape flag on it runs down to the starter solenoid. The other red one runs to the back of the alternator.

F-JunctionBox.jpg
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"Ceramic looking thing" is not a junction block, but a resistor (ballast resistor in series with ignition coil primary).. Where does other ignition switch wire connect? Do you have any spare 6v or 12v bulbs/headlights around? If so, connect one from inside ammeter terminal to ground & see if meter shows a reading.
 
(quoted from post at 15:14:03 03/07/10)
(quoted from post at 17:28:49 03/07/10) Here's a pic. Prior to me switching, the two wires on the inside post were on the outside post. So, am I correct in assuming the the ceramic looking thing is the junction box mentioned in wiring diagrams? By the way, that little yellow wire runs to the outside post on the key switch.

The red wire with the tape flag on it runs down to the starter solenoid. The other red one runs to the back of the alternator.

F-JunctionBox.jpg
Click to expand...

"Ceramic looking thing" is not a junction block, but a resistor (ballast resistor in series with ignition coil primary).. Where does other ignition switch wire connect? Do you have any spare 6v or 12v bulbs/headlights around? If so, connect one from inside ammeter terminal to ground & see if meter shows a reading.
Click to expand...

That other inside yellow wire on the key switch is spliced directly to that orange wire you see on the ballast resister. The orange goes no where else. So, consider that inside wire on the switch going right to that top terminal on the resister.
 
(quoted from post at 18:19:41 03/08/10)
(quoted from post at 15:14:03 03/07/10)
(quoted from post at 17:28:49 03/07/10) Here's a pic. Prior to me switching, the two wires on the inside post were on the outside post. So, am I correct in assuming the the ceramic looking thing is the junction box mentioned in wiring diagrams? By the way, that little yellow wire runs to the outside post on the key switch.

The red wire with the tape flag on it runs down to the starter solenoid. The other red one runs to the back of the alternator.

F-JunctionBox.jpg
Click to expand...

"Ceramic looking thing" is not a junction block, but a resistor (ballast resistor in series with ignition coil primary).. Where does other ignition switch wire connect? Do you have any spare 6v or 12v bulbs/headlights around? If so, connect one from inside ammeter terminal to ground & see if meter shows a reading.
Click to expand...

That other inside yellow wire on the key switch is spliced directly to that orange wire you see on the ballast resister. The orange goes no where else. So, consider that inside wire on the switch going right to that top terminal on the resister.
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Assuming that the two big red wires go to batt & alt as you have indicated, then the meter should show a discharge when current flows from battery to load, as in RED (in this case apparently only the ignition, & the points must be closed for that to happen).
Then when running and alt putting out, current should flow as in GREEN, from alt thru ammeter to battery, showing a charge condition (+).
Try wiring a lamp as shown from load side of ammeter to ground (I barked a bolt) & look for meter movement. If nothing, try other ammeter terminal, & if it reads then, I suggest that you have the two big wires reversed, i.e., the one you think is batt is really alt & visa verse.
ammeter_prob1.jpg
 
You must have missed the post. Originally the red wire and the yellow wire were on the outside post of the gauge. I tried switching those two to the inside post as you see now. That doesn't work either.

I "tape flagged" the one red wire so I wouldn't get the two mixed up.
 
(quoted from post at 19:37:06 03/08/10) You must have missed the post. Originally the red wire and the yellow wire were on the outside post of the gauge. I tried switching those two to the inside post as you see now. That doesn't work either.

I "tape flagged" the one red wire so I wouldn't get the two mixed up.
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Yes, I saw that. But you will notice that I spoke of swapping the two reds........not moving the yellow. At any rate, do the lamp connections I spoke of as they will give us information to work from.
 
(quoted from post at 16:42:58 03/08/10)
(quoted from post at 19:37:06 03/08/10) You must have missed the post. Originally the red wire and the yellow wire were on the outside post of the gauge. I tried switching those two to the inside post as you see now. That doesn't work either.

I "tape flagged" the one red wire so I wouldn't get the two mixed up.
Click to expand...
Yes, I saw that. But you will notice that I spoke of swapping the two reds........not moving the yellow. At any rate, do the lamp connections I spoke of as they will give us information to work from.
Click to expand...

I don't think you understand, originally the red (flagged) wire was on the inside post and the other red and the yellow were on the outside post.

In the picture of the gauge you see the wires after I switched them when I installed the new gauge and it did not work.

I wired a tail light bulb as you suggested. When I touched the flagged wire post the light lit and the amp gauge moved maybe a little less than a sixteenth toward the plus side.

When I touched the other post the lamp also lit but the gauge did nothing at all. Should both of those gauge posts be able to light the test bulb like that?

So, since gauge did move a little toward the plus side, I'm thinking I should switch the red and yellow back to the outside post and the flagged red back to the inside post and the test bulb should make the gauge read a little to the minus side.

But that is how it was originally wired and the old gauge and the new gauge did not work. So, I'm stumped.
 
(quoted from post at 20:36:36 03/08/10)
(quoted from post at 16:42:58 03/08/10)
(quoted from post at 19:37:06 03/08/10) You must have missed the post. Originally the red wire and the yellow wire were on the outside post of the gauge. I tried switching those two to the inside post as you see now. That doesn't work either.

I "tape flagged" the one red wire so I wouldn't get the two mixed up.
Click to expand...
Yes, I saw that. But you will notice that I spoke of swapping the two reds........not moving the yellow. At any rate, do the lamp connections I spoke of as they will give us information to work from.
Click to expand...

I don't think you understand, originally the red (flagged) wire was on the inside post and the other red and the yellow were on the outside post.

In the picture of the gauge you see the wires after I switched them when I installed the new gauge and it did not work.

I wired a tail light bulb as you suggested. When I touched the flagged wire post the light lit and the amp gauge moved maybe a little less than a sixteenth toward the plus side.

When I touched the other post the lamp also lit but the gauge did nothing at all. Should both of those gauge posts be able to light the test bulb like that?

So, since gauge did move a little toward the plus side, I'm thinking I should switch the red and yellow back to the outside post and the flagged red back to the inside post and the test bulb should make the gauge read a little to the minus side.

But that is how it was originally wired and the old gauge and the new gauge did not work. So, I'm stumped.
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1) Leave yellow wire where it is. Do not move yellow.
2)move flagged red wire to inside
3)move other red wire to outside.
Then you will have flagged red AND yellow on inside and red (not flagged) wire on outside.

With points closed & key on, does ammeter show (-)?
When key on & cranking (prior to engine firing) is ammeter jiggling toward (-)?

"Should both of those gauge posts be able to light the test bulb like that?"

Yes, there is no perceptible difference in voltage between those two terminals.
 

OK, switched red wires only.

Points closed. turn key to on position only. Ammeter.......no movement.

Cranking before starting. Ammeter........no movement.

Engine started and running. Ammeter......no movement.

I'm stumped. :cry:
 
(quoted from post at 14:00:30 03/09/10)
OK, switched red wires only.

Points closed. turn key to on position only. Ammeter.......no movement.

Cranking before starting. Ammeter........no movement.

Engine started and running. Ammeter......no movement.

I'm stumped. :cry:
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OK. The lamp draws enough current to make the ammeter needle move. But apparently the ignition does not draw sufficient current? What is the scale on that ammeter? +/- 60amps or what?
 
-30 to + 30 same as the old one that didn't work. It just doesn'tmake any sense why it doesn't work.
 
(quoted from post at 14:31:59 03/09/10) -30 to + 30 same as the old one that didn't work. It just doesn'tmake any sense why it doesn't work.
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ith a 30/30 scale, one minor division is 5 amps, so don't expect to see much movement. I don't know that bulb number that you used in the lamp test, but if a tail light/stop light such as #1157, you are in about the 2 amp range.....not much movement. Now, you may be thinking, well, what about the alternator...that ought to show. As of this time, I do not know whether the alternator works or not.
If you are careful & fast, you can obtain a large current (surely make meter jump) by quickly dragging a grounded wire across either ammeter terminal and making an arc/spark. Just like the lamp test, the terminal which shows no movement is the one connected to the battery & the one showing movement is the LOAD terminal of ammeter (where ign sw & alternator should be connected). I bet you see meter movement.
 
(quoted from post at 11:50:28 03/09/10)
(quoted from post at 14:31:59 03/09/10) -30 to + 30 same as the old one that didn't work. It just doesn'tmake any sense why it doesn't work.
Click to expand...
ith a 30/30 scale, one minor division is 5 amps, so don't expect to see much movement. I don't know that bulb number that you used in the lamp test, but if a tail light/stop light such as #1157, you are in about the 2 amp range.....not much movement. Now, you may be thinking, well, what about the alternator...that ought to show. As of this time, I do not know whether the alternator works or not.
If you are careful & fast, you can obtain a large current (surely make meter jump) by quickly dragging a grounded wire across either ammeter terminal and making an arc/spark. Just like the lamp test, the terminal which shows no movement is the one connected to the battery & the one showing movement is the LOAD terminal of ammeter (where ign sw & alternator should be connected). I bet you see meter movement.
Click to expand...

Actually the bulb I used was an 1157 spare for my Ford van. I just arced the terminals quickly as you advised. Outer post now with non flagged red wire arced but did not move gauge.

Inner post with the flagged wire jumped the needle all the way to -30.

Of course the alternator is working it has been ever since I bought the tractor, my battery is not going down.

So your thinking that my 12 volt system on that tractor just won't work that + or - 30 gauge? What should be on it? What is a stock gauge?

Is there just no way to have a working ammeter when you have a 12 volt system? I just can't understand that.

I know you're trying your best to help and I do appreciate it, I'm just getting a little frustrated now.
 
(quoted from post at 15:13:00 03/09/10)
(quoted from post at 11:50:28 03/09/10)
(quoted from post at 14:31:59 03/09/10) -30 to + 30 same as the old one that didn't work. It just doesn'tmake any sense why it doesn't work.
Click to expand...
ith a 30/30 scale, one minor division is 5 amps, so don't expect to see much movement. I don't know that bulb number that you used in the lamp test, but if a tail light/stop light such as #1157, you are in about the 2 amp range.....not much movement. Now, you may be thinking, well, what about the alternator...that ought to show. As of this time, I do not know whether the alternator works or not.
If you are careful & fast, you can obtain a large current (surely make meter jump) by quickly dragging a grounded wire across either ammeter terminal and making an arc/spark. Just like the lamp test, the terminal which shows no movement is the one connected to the battery & the one showing movement is the LOAD terminal of ammeter (where ign sw & alternator should be connected). I bet you see meter movement.
Click to expand...

Actually the bulb I used was an 1157 spare for my Ford van. I just arced the terminals quickly as you advised. Outer post now with non flagged red wire arced but did not move gauge.

Inner post with the flagged wire jumped the needle all the way to -30.

Of course the alternator is working it has been ever since I bought the tractor, my battery is not going down.

So your thinking that my 12 volt system on that tractor just won't work that + or - 30 gauge? What should be on it? What is a stock gauge?

Is there just no way to have a working ammeter when you have a 12 volt system? I just can't understand that.
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Great!! That means that your meter is wired correctly and that non-flagged wire is from battery and that flagged wire should connect to alternator. Further it indicates that meter is capable of reading current.
Now, need to verify that flagged wire does in fact go to alternator. You can at least prove that it is in the circuit by repeating that arc/spark scratch test at the alternator stud terminal while observing the ammeter for the same discharge indication.
 

OK, did that. The terminal on back of the alternator jumped the needle to -30 the same way.
 
(quoted from post at 15:36:39 03/09/10)
OK, did that. The terminal on back of the alternator jumped the needle to -30 the same way.
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OK, so now it appears that you are done with ammeter wiring and at least the main connection to alternator. Does your alternator look like this & if so does it have one wire to stud terminal & no other connections or does it have connections to the two prong plug?
Alternator_bobs_Harness3.jpg
 
(quoted from post at 12:41:59 03/09/10)
(quoted from post at 15:36:39 03/09/10)
OK, did that. The terminal on back of the alternator jumped the needle to -30 the same way.
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OK, so now it appears that you are done with ammeter wiring and at least the main connection to alternator. Does your alternator look like this & if so does it have one wire to stud terminal & no other connections or does it have connections to the two prong plug?
Alternator_bobs_Harness3.jpg
Click to expand...

OK, my alternator is a Delco Remy and looks just like that one. All it has is the one wire on that back stud that you had me arc test. There are the two flat terminals at the top for a plastic plug like that one but nothing is there. No wires or plug. I looked around and there is no plug that could have just slipped off, just not there.
 
There is a pretty good chance that you have what is called a one wire alternator. A modified version of the DelcO 10-si. Some of these have to be revved quite high to get them to kick in. Alternatively you can get it up to speed & momentarily jumper a wire from the big stud terminal to the spade on left (viewing from rear) numbered #1 in the picture and this will start it to charging if alternator is good. If this doesn't work, take alternator to auto supply store & let them test it...generally free testing. Also, if you have a volt meter, you can measure big stud terminal and see if voltage increases after starting tractor (should see a volt or more increase).
 
(quoted from post at 14:01:20 03/09/10) There is a pretty good chance that you have what is called a one wire alternator. A modified version of the DelcO 10-si. Some of these have to be revved quite high to get them to kick in. Alternatively you can get it up to speed & momentarily jumper a wire from the big stud terminal to the spade on left (viewing from rear) numbered #1 in the picture and this will start it to charging if alternator is good. If this doesn't work, take alternator to auto supply store & let them test it...generally free testing. Also, if you have a volt meter, you can measure big stud terminal and see if voltage increases after starting tractor (should see a volt or more increase).
Click to expand...

I don't understand this. You're saying my alternator is not charging? Why is my battery not going dead?

I do have a volt meter. are you saying red probe on the stud on the back of the alternator and black probe to any ground?
 
(quoted from post at 18:03:18 03/09/10)
(quoted from post at 14:01:20 03/09/10) There is a pretty good chance that you have what is called a one wire alternator. A modified version of the DelcO 10-si. Some of these have to be revved quite high to get them to kick in. Alternatively you can get it up to speed & momentarily jumper a wire from the big stud terminal to the spade on left (viewing from rear) numbered #1 in the picture and this will start it to charging if alternator is good. If this doesn't work, take alternator to auto supply store & let them test it...generally free testing. Also, if you have a volt meter, you can measure big stud terminal and see if voltage increases after starting tractor (should see a volt or more increase).
Click to expand...

I don't understand this. You're saying my alternator is not charging? Why is my battery not going dead?

I do have a volt meter. are you saying red probe on the stud on the back of the alternator and black probe to any ground?
Click to expand...

It is certainly suspect, since the ammeter shows no charge & it appears that we have determined that it is wired correctly. On ignition only, these tractors will run in excess of ~40 hours before battery goes dead. Have you had it running that long since battery was new or last on a wall charger? Yes, red to alt stud & black to any ground (alternator case is good). From stopped engine to running at speed, the voltage should show an increase of a volt or more, for example, from 12.5 to 13.5.
 
(quoted from post at 15:09:13 03/09/10)
(quoted from post at 18:03:18 03/09/10)
(quoted from post at 14:01:20 03/09/10) There is a pretty good chance that you have what is called a one wire alternator. A modified version of the DelcO 10-si. Some of these have to be revved quite high to get them to kick in. Alternatively you can get it up to speed & momentarily jumper a wire from the big stud terminal to the spade on left (viewing from rear) numbered #1 in the picture and this will start it to charging if alternator is good. If this doesn't work, take alternator to auto supply store & let them test it...generally free testing. Also, if you have a volt meter, you can measure big stud terminal and see if voltage increases after starting tractor (should see a volt or more increase).
Click to expand...

I don't understand this. You're saying my alternator is not charging? Why is my battery not going dead?

I do have a volt meter. are you saying red probe on the stud on the back of the alternator and black probe to any ground?
Click to expand...

It is certainly suspect, since the ammeter shows no charge & it appears that we have determined that it is wired correctly. On ignition only, these tractors will run in excess of ~40 hours before battery goes dead. Have you had it running that long since battery was new or last on a wall charger? Yes, red to alt stud & black to any ground (alternator case is good). From stopped engine to running at speed, the voltage should show an increase of a volt or more, for example, from 12.5 to 13.5.
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OK, now it's getting strange. With the engine not running it measured 12.5 or 6. Now with the engine running at 1800 rpm it measured 14.6. This is with the volt meter red terminal to big post and black to alternator case.

Now here is the strange part. I looked at the ammeter while the tractor was running and the needle was actually reading about the same 14.6 on the plus side.

I actually have to use the tractor now to do some road work on my place so I'll keep an eye on the ammeter.

Thank you so much for all your efforts, I'll let you know if it continues to work
 
OK, here's the latest. I went out an worked the tractor for an hour and a half. Tractor ran fine as usual. Ammeter showed a 1/64" to maybe a 1/32" towards the plus side.

I played with it a bit when I finished working. I took that red wire off the back of the alternator and cleaned the post and the wire terminal real good.

Sitting on the tractor turning the key on and off shows the needle maybe a 1/32" towards the minus. Cranking the engine over doesn't seem to make the needle move. When it starts, the needle stays a sixty fourth to maybe a thirty second to the plus side. That's at idle. When I move it up to full throttle the needle will jump to about 25 on the plus and slowly start back down. In maybe two seconds it's again at maybe a thirty second on the plus side.

This is kind of funny. If I let it sit and idle a couple minutes and run the throttle back to full, the needle won't jump up to 25 like that again.

It will only jump up to 25 like that when I stop the engine and sit maybe five seconds. Then start it up at maybe 600 rpm. Turn up to full throttle and it will jump again to 25 and slowly go back down. So, it only does that when the engine has been off a few seconds.

Working the whole hour and a half the needle stayed just a little on the plus side like I said between a sixty fourth and a thirty second.

Is this all I can expect out of this -30 to +30 ammeter? If I put one in that read -60 to +60 would I get more perceptible needle readings?
 
(quoted from post at 20:38:33 03/09/10) OK, here's the latest. I went out an worked the tractor for an hour and a half. Tractor ran fine as usual. Ammeter showed a 1/64" to maybe a 1/32" towards the plus side.

I played with it a bit when I finished working. I took that red wire off the back of the alternator and cleaned the post and the wire terminal real good.

Sitting on the tractor turning the key on and off shows the needle maybe a 1/32" towards the minus. Cranking the engine over doesn't seem to make the needle move. When it starts, the needle stays a sixty fourth to maybe a thirty second to the plus side. That's at idle. When I move it up to full throttle the needle will jump to about 25 on the plus and slowly start back down. In maybe two seconds it's again at maybe a thirty second on the plus side.

This is kind of funny. If I let it sit and idle a couple minutes and run the throttle back to full, the needle won't jump up to 25 like that again.

It will only jump up to 25 like that when I stop the engine and sit maybe five seconds. Then start it up at maybe 600 rpm. Turn up to full throttle and it will jump again to 25 and slowly go back down. So, it only does that when the engine has been off a few seconds.

Working the whole hour and a half the needle stayed just a little on the plus side like I said between a sixty fourth and a thirty second.

Is this all I can expect out of this -30 to +30 ammeter? If I put one in that read -60 to +60 would I get more perceptible needle readings?
Click to expand...
o, if you put a 60A meter on there, it will read even less. It all sounds like it is working as it should. When you use the starter it drains some amount of energy from the battery & when engine starts, the alternator replaces that amount of energy. After that, all it needs to do is keep the battery topped off & supply the small ignition current. Your meter is connected as a net-reading ammeter, meaning it measures only whatever current is going into or out of battery (starter excepted). So, once that initial starter drain is replaced, the battery basically sits there for the rest of the run, neither supplying or absorbing current, hence, not much of anything showing on ammeter.......just as it should be.
 
OK, I guess all is well then. I guess I'm just used to the ammeter in my Ford van. I can see very well when it's charging as it should. Something on like the air conditioner and you see the needle go down.

This ammeter is just not that much help, I mean, let's face it, if it ever does go imperceptibly into the minus while I'm working I'm just not going to notice anything. So, if my alternator just quits entirely while running, should I at least get some kind of reading that I will notice?

The guy right up the road from me has an 8N. He converted his to 12 volt also. I'll have to ask him about his ammeter next time I see him.

I'd still like to have a temp gauge also. I'm not going to press my luck by drilling a hole in the head for a sensor though. I guess I could try one in the top radiator hose like I've read about.

I like your explanation about the battery just sitting not doing much of anything. I guess it's better to have something doing nothing than have something not doing what it's supposed to do. :lol:
 
I had a similar problem to yours . When I converted my 8N to 12 volts, the ammeter would read about 1 amp positive right after starting and then quickly drop to 0. I checked the voltage at the battery while running and it read 14.6 volts. I took this to mean that all is well and the battery is charging.

I switched the ammeter out in favor of a volt meter and monitor it that way. I think it works much better that way, but I know many others prefer the ammeter. Mine has been this way for over a year now - started every time over this winter with temps down to about 10 degrees F or so. The battery checks fully charged with an hydrometer.

Kurt-NEPA
 
(quoted from post at 18:42:57 03/09/10) I had a similar problem to yours . When I converted my 8N to 12 volts, the ammeter would read about 1 amp positive right after starting and then quickly drop to 0. I checked the voltage at the battery while running and it read 14.6 volts. I took this to mean that all is well and the battery is charging.

I switched the ammeter out in favor of a volt meter and monitor it that way. I think it works much better that way, but I know many others prefer the ammeter. Mine has been this way for over a year now - started every time over this winter with temps down to about 10 degrees F or so. The battery checks fully charged with an hydrometer.

Kurt-NEPA
Click to expand...

What did the ammeter do before you switched to 12 volts?
 
Cary, if you want to see a bit more Positive reading on the ammeter, the re-positioning of the yellow wire to the opposite ammeter post will change it to a meter which reads ALL alternator current (load + battery charging current). Actually some of the 12v conversion kits instruct that you do it that way. I will point out that the tractor rolled out of the Ford factory wired with a NET-reading ammeter, as it is currently wired on your tractor. If you do change it to read ALL alternator current, then you will never see a negative reading unless your alternator goes to west to meet it's ancestors.
 
(quoted from post at 20:08:02 03/09/10) Cary, if you want to see a bit more Positive reading on the ammeter, the re-positioning of the yellow wire to the opposite ammeter post will change it to a meter which reads ALL alternator current (load + battery charging current). Actually some of the 12v conversion kits instruct that you do it that way. I will point out that the tractor rolled out of the Ford factory wired with a NET-reading ammeter, as it is currently wired on your tractor. If you do change it to read ALL alternator current, then you will never see a negative reading unless your alternator goes to west to meet it's ancestors.
Click to expand...

JMOR,

You sound like a guy who really knows what the heck he's talking about. Your explanations were really detailed and didn't leave anything to wonder about. I really appreciate all your help and will leave it as is. Don't want to press my luck. I'm so glad I found this forum.
 
Before I converted to 12V, the ammeter would read about 3 or 4 amps at 1200 rpm right after starting. Then in about 3 or 4 minutes drop to about 0 or just slightly above. When I first turned the key on (before starting) it would read a negative 1 or 2 amps. I was never sure my 6V generator and regulator were working well, but it kept the battery charged.

With the 12 volt system the tractor pulls about 1/2 the amps it did on 6 volt. It was so low that I could hardly read it on the ammeter. A volt meter is much more telling (at least to me). If I had lights it might be a different story.

BTW, the conversion to 12 volts "cured" a hard start problem due to low compression until I could get the engine rebuilt. After the rebuild, I'm sure I could have gone back to 6 volts, but my alternator was new and the old genny and regulator would have needed some attention. I've never regretted the conversion.

Kurt-NEPA
 
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