Question for you 12V sparkies.

Adirondack case guy · Jul 10, 2017

I an in the process of reviving a Case G310G dozer after an engine fire. All the electrical components were destroyed with the exception of the starter. Radiator, oil bath air cleaner, fuel pump, and carb also destroyed. I have been able to acquire used distributer, and carb.
Prior to the fire someone removed the generator and VR and just ran a 10G wire from the single stud alternator directly back to the bat box where they bolted in a 30A circuit breaker and then attached the leads to the positive post of the battery, which took the entire ignition switch and gauges out of the charge circuit.
I asked the owner of the dozer to pick up new water temp, oil pressure and volt meter gauges. When he got delivery from the NAPA store they just sent him one of those 3 gauge assys. with an amp meter. They also substituted singe 0 bat cables verses the double 0 that I asked him to get, plus they put in those rotten clamp on battery ends when the list clearly said swedge/soder ends. I was not happy, but that is another story.
Here lies my question. I want to bring the amp meter into the charge loop. It is a 60A gauge, and the alt. is rated for 63A maximum output. If I run the new 10G wire from the alt. to the pos. post on the ammeter, and then run the wire from the neg. terminal on ammeter down the starter solenoid terminal that the bat lead is connected to, will everything work??? Would you put the ignition switch into the charge circuit also??? Would you incorporate a 30A breaker into this charge circuit like before??? The only electrical load is the lighting system and the ignition circuit. Chances of the lights being user are slim. A simple volt meter would have been much better in my opinion, but I have to deal with what was brought to me.
Loren

old · Jul 10, 2017

I almost always get this backwards but if it does not show a charge just move the alternator wire to the other side. On one side of the amp gauge you have an input form the battery. On the other side you have a wire going to the ignition switch and you hook the alternator charge wire to that post also.

JDEM · Jul 10, 2017

The alternator is supposed to be hooked to 8 gauge wire along with a 60-70 amp fusible link (12 gauge fuse wire).

The breaker, fuse, or fusible like is supposed to match the wire max ampacity so it blows before the wire can start a fire. For that - 30 amps matches 10 gauge wire. So what you mention is safe. Just not correct if full charge capability is wanted.

Steve@Advance · Jul 10, 2017

Only the battery lead goes to one side of the amp meter.

The alternator and everything else goes to the other.

I would not run the alternator through the circuit breaker. It will probably trip if the battery was low, and that is not good for an alternator. Put the CB on the accessory/ignition feed so it protects everything upstream from there.

Bob Bancroft · Jul 10, 2017

After a neighbor burned up his MF 65(we brought it back to life) I started paying attention to the fact that our old tractors have no protection from a short in the system. Usually the only protection is a 20A fuse in the lighting circuit. I have taken to putting a fuse or circuit breaker as close as practical to where the main feed is off the solenoid. Since then another friend came close to losing his ACD15II. Apparently the cut out side of the regulator stuck closed on shut down and was not noticed. Both heavy wires to the ammeter had the insulation burned off, and the generator was toast. There is now an aircraft circuit breaker mounted in the side panel close to where the power comes off the solenoid. What's nice about these circuit breakers is that they operate like a household type- you can turn them off manually, and they have to be manually reset.

Stephen Newell · Jul 10, 2017

Isn't it suppose to have a coil resister? I don't see one.

Hobo,NC · Jul 10, 2017

I would put a voltmeter on it and move on with life, life will be good...

Janicholson · Jul 10, 2017

10 gauge from amp meter to starter solenoid hot terminal, from load side of amp meter to everything else. Use the fuse. THe gauge will be just fine for that alt. Gauge lettering is not standardized. When you hook it up to the starter as above, use a 12v head light bulb or fan blower motor or? to load the opposite side to ground. if the gauge reads discharge all is well. If it shows charge, it is backwards. There is no logic involved. Jim

Geo-TH,In · Jul 11, 2017

Loren,
I use a 3 wire alternator on my Farmall and Jubilee, cheaper. I was told I would regret using a 30 amp breaker on alternator. So far it hasn't caused a problem. I also fused my lights and ign coil. I take power from Ign circuit, run it to idiot light to alternator. So when I turn key on, I can see the light, telling me my coil is powered up, ign fuse is good.

I replaced all my wires because my 12v conversion from previous owner left out the ammeter. I can't remember just how I wired in Ammeter. I didn't run the current going to starter through meter. I think it was easier for me to run the ammeter back to the +12v. No big deal if you get ammeter wired in backwards, it will show charge when you turn lights on instead of discharge.

I'm sure someone has wiring diagram for you.
good luck.
geo.

Bret4207 · Jul 11, 2017

If you don't run the one wire alternator "hot" wire through the switch, then you'll need a diode to keep the alt from draining the battery. Some alts come with the diode installed, some don't. I'm going through this myself right now. Those diodes are readily available and under $10.00. They can be soldered and heat shrinked right into the hot wire. Another option is to use a standard 3 wire alt or use a battery disconnect switch on the ground.

I've never run a circuit breaker in an alt line on a tractor. Not enough sensitive electronics to warrant it IMO. A fuse, maybe, but it's got to be a good sized fuse.

John T · Jul 11, 2017

Its pretty simple wiring for an alternator and I'm assuming its NEG ground.

Alternators output to the Ammeter,,,,,,,,,,,Ammeter's other terminal to hot ungrounded battery post, often via where the big battery cable attaches to a starter switch or solenoid BAT INPUT (NOT starter OUTPUT side) or the battery itself.

To correctly measure charging current INTO battery or discharging current OUT of battery, the ammeter is wired in series BETWEEN alternator (and other loads see below) and battery.

LOADS like lights or ignition etc are wired/fed off the Alternator side of the ammeter. Proper fuse protection should be used for load circuits. In order for the ammeter to correctly measure NET charging current INTO or discharging current OUT of the battery (which is on other side of ammeter) they are wired/fed off the alternator side of the ammeter. The ONLY circuit on the other side of ammeter is to the battery IE don't feed loads from there as their current draw wouldn't be registered by the ammeter WELL DUH if current is NOT passing through the ammeter it cant measure it lol

NOTE Often I see 10 Gauge wire from the alternator BUT BE AWARE if its say a 60 amp alternator, 10 Gauge "may" be (subject to type of wire and insulation and jacketing or enclosure) a bit light, Id prefer 8 or even 6 gauge from alternator to ammeter then to battery. SURE 10 WILL WORK don't anyone have a calf now. Many non sparkies may not realize the ampacity of a single conductor in free air is greater then if its enclosed or jacketed, so a 10 gauge single conductor in free air has more ampacity then the 30 amps many take for granted.

YOUR SPECIFIC QUESTIONS:

Here lies my question. I want to bring the amp meter into the charge loop. It is a 60A gauge, and the alt. is rated for 63A maximum output. If I run the new 10G wire from the alt. to the pos. post on the ammeter, and then run the wire from the neg. terminal on ammeter down the starter solenoid terminal that the bat lead is connected to, will everything work???

Ive seen weird labels on ammeters, but on many if you're at NEG ground Id think the - goes to alternator and + of ammeter to
+ of battery BUT CANT GUARANTEE THAT, if it registers backwards simply reverse the leads.

Id consider bigger wire, see above.

YES it will "work"

"Would you put the ignition switch into the charge circuit also???"

I would feed the ignition switch and other loads off the alternator side of the ammeter, see above

John T

JDEM · Jul 11, 2017

You've got me confused with your comment . . ."If you don't run the one wire alternator "hot" wire through the switch, then
you'll need a diode to keep the alt from draining the battery. "

All a "one-wire" alterntor is -is a stock alternator with a self-exciting regulator swapped in. This "one wire" setup uses
no outside field current and draws nothing from the system when idle. I.e. no diode or resistor needed. It relies on
residual magnetism inside the alternator to get itself started.

A standard SI series Delco with the OEM three wire hookup uses a field-current lead from the ignition to get it started.
This does require some sort of isolation to prevent drain. It can be done with a relay, a diode, a resistor, or even just
some trick wiring. If an ignition switch is used that has both an IGN and a ACC terminal - using ACC to power the field is
all that is needed to prevent drain.

John T · Jul 11, 2017

Rich, FWIW I agree with Steve. What I call the SUPPLY side of the Ammeter wires ONLY to Battery (or solenoids BAT side). What I call the LOAD side of the ammeter wires to Alternator or BAT terminal on a VR etc., PLUS feeds loads like lights and ignition etc. BAT on one side, alternator PLUS loads on other side. If it happens to be a generator and a 4 terminal VR with a LOAD terminal, loads are then fed there instead.

That way the ammeter correctly measures net charging current INTO or discharging current OUT OF the battery. If loads were on same side of ammeter as battery, their current draw isn't seen or measured by the ammeter

Use of the terms Supply and Load side eliminates the problem of Pos or Neg ground

If it reads backwards reverse the leads

John T

JMOR · Jul 11, 2017

(quoted from post at 08:31:29 07/11/17) You've got me confused with your comment . . ."If you don't run the one wire alternator "hot" wire through the switch, then
you'll need a diode to keep the alt from draining the battery. "

All a "one-wire" alterntor is -is a stock alternator with a self-exciting regulator swapped in. This "one wire" setup uses
no outside field current and draws nothing from the system when idle. I.e. no diode or resistor needed. It relies on
residual magnetism inside the alternator to get itself started.
[color=cyan:19239f3c5d]"...and draws nothing from the system when idle."[/color:19239f3c5d] [color=red:19239f3c5d]This is NOT the case with either 3 wire or one wire Delco 10-SI, as the voltage sensing circuit inside the internal VR ALWAYS draws current, although very small.[/color:19239f3c5d]
A standard SI series Delco with the OEM three wire hookup uses a field-current lead from the ignition to get it started.
[color=cyan:19239f3c5d]This does require some sort of isolation to prevent drain.[/color:19239f3c5d] [color=red:19239f3c5d]To "prevent drain" is NOT the purpose of these wiring arrangements on the excite wire, but rather to prevent the alternator from feeding voltage/current to the coil after ign is turned off, which can keep engine running even with ign off[/color:19239f3c5d]. It can be done with a relay, a diode, a resistor, or even just
some trick wiring. If an ignition switch is used that has both an IGN and a ACC terminal - using ACC to power the field is
all that is needed to prevent drain.

rvirgil_KS · Jul 11, 2017

Resistor is only used in 12 volt system with 6 volt coil or "12 volt external resistor required" (1 1/2 ohms across + - primary)

No resistor used with direct "12 volt no external resistor required" coil (3 ohms across + - primary)

old · Jul 11, 2017

That is what I said wasn't it????????????

John T · Jul 11, 2017

I agree with Steve, glad to help and even better, he and I had basically the same thoughts YAYYYYYYYYYYY LOL. It is indeed "mostly" what you said Rich. Hopefully, now you will no longer as you said "almost always get this backwards". Hey I've been guilty of the same type mistakes myself and it wont be the last time grrrrrrrrrrrrrr

Thanks for posting and the feedback

Best wishes n God Bless Rich, take care

John T

old · Jul 11, 2017

Most of my backwards doing on the amp gauge is hooking it up so when it is charging it show * charge and when it is discharging it shows + which I can care the least about either way I know it is working or not working

JMOR · Jul 11, 2017

(quoted from post at 08:31:29 07/11/17) You've got me confused with your comment . . ."If you don't run the one wire alternator "hot" wire through the switch, then
you'll need a diode to keep the alt from draining the battery. "

All a "one-wire" alterntor is -is a stock alternator with a self-exciting regulator swapped in. This "one wire" setup uses
no outside field current and draws nothing from the system when idle. I.e. no diode or resistor needed. It relies on
residual magnetism inside the alternator to get itself started.
{{"...and draws nothing from the system when idle." This is NOT the case with either 3 wire or one wire Delco 10-SI, as the voltage sensing circuit inside the internal VR ALWAYS draws current, although very small.}}
A standard SI series Delco with the OEM three wire hookup uses a field-current lead from the ignition to get it started.
This does require some sort of isolation to prevent drain. {{To "prevent drain" is NOT the purpose of these wiring arrangements on the excite wire, but rather to prevent the alternator from feeding voltage/current to the coil after ign is turned off, which can keep engine running even with ign off.}} It can be done with a relay, a diode, a resistor, or even just
some trick wiring. If an ignition switch is used that has both an IGN and a ACC terminal - using ACC to power the field is
all that is needed to prevent drain.
{{just to set record straight for future readers of archives}}

Bret4207 · Jul 12, 2017

(quoted from post at 09:31:29 07/11/17) You've got me confused with your comment . . ."If you don't run the one wire alternator "hot" wire through the switch, then
you'll need a diode to keep the alt from draining the battery. "

All a "one-wire" alterntor is -is a stock alternator with a self-exciting regulator swapped in. This "one wire" setup uses
no outside field current and draws nothing from the system when idle. I.e. no diode or resistor needed. It relies on
residual magnetism inside the alternator to get itself started.

A standard SI series Delco with the OEM three wire hookup uses a field-current lead from the ignition to get it started.
This does require some sort of isolation to prevent drain. It can be done with a relay, a diode, a resistor, or even just
some trick wiring. If an ignition switch is used that has both an IGN and a ACC terminal - using ACC to power the field is
all that is needed to prevent drain.

I'm not clear on the specifics enough to try and speak in electrical engineer terms, but I do know that at least SOME 1 wire alts will drain the battery if there's no switch or diode type thingy in the line. WHY it does it when it's not supposed to I can't say, but one of the kits I bought to switch a 3 wire to a one wire specifically mentioned this issue. That is the one that I have to unhook the battery cable positive post on or I will have a dead batt in the morning. I'm going to add a battery disconnect to that particular Cockshutt.

JMOR · Jul 12, 2017

(quoted from post at 08:28:00 07/12/17)

(quoted from post at 09:31:29 07/11/17) You've got me confused with your comment . . ."If you don't run the one wire alternator "hot" wire through the switch, then
you'll need a diode to keep the alt from draining the battery. "

All a "one-wire" alterntor is -is a stock alternator with a self-exciting regulator swapped in. This "one wire" setup uses
no outside field current and draws nothing from the system when idle. I.e. no diode or resistor needed. It relies on
residual magnetism inside the alternator to get itself started.

A standard SI series Delco with the OEM three wire hookup uses a field-current lead from the ignition to get it started.
This does require some sort of isolation to prevent drain. It can be done with a relay, a diode, a resistor, or even just
some trick wiring. If an ignition switch is used that has both an IGN and a ACC terminal - using ACC to power the field is
all that is needed to prevent drain.

Click to expand...

I'm not clear on the specifics enough to try and speak in electrical engineer terms, but I do know that at least SOME 1 wire alts will drain the battery if there's no switch or diode type thingy in the line. WHY it does it when it's not supposed to I can't say, but one of the kits I bought to switch a 3 wire to a one wire specifically mentioned this issue. That is the one that I have to unhook the battery cable positive post on or I will have a dead batt in the morning. I'm going to add a battery disconnect to that particular Cockshutt.

s I said in my other post in this thread, they ALL draw some minuscule current (generally sub-milliampere) via the VR sense circuit when not in use, however, this is so small that it should require years to totally drain even a 60A-H battery, so if yours "drains overnight", I would say that something is wrong with it.

Bret4207 · Jul 12, 2017

I had another one on a Ford 800 that did the same thing until I ran it through the switch. I dunno why, but it happens.

Question for you 12V sparkies.

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