Ford 640 not charging

nashranch

Well-known Member
My newly purchased 640 shows no charge on the amp meter. The previous owner had a 12 volt in it and hooked up negative ground. Also both the generator and starter have stickers on them from a local auto electric shop. The tractor does start up and run real well. So I guess the starter is turning the right direction. Are there resistance readings I can get to check out generator? Also does anybody have a good wiring diagram for a 640 12v neg. ground system?
 
The starter will turn the right direction regardless of battery
polarity. What do the stickers from the shop say?
I don't know of any resistance readings you can use, but you
can measure voltage across the battery terminals.
Measure it not running, then start it and measure it running.
Usually about mid-throttle. It should go up from ~12.4 to ~14.
 
(quoted from post at 18:42:29 10/28/17) The starter will turn the right direction regardless of battery
polarity. What do the stickers from the shop say?
I don't know of any resistance readings you can use, but you
can measure voltage across the battery terminals.
Measure it not running, then start it and measure it running.
Usually about mid-throttle. It should go up from ~12.4 to ~14.

I guess what I do royse is hook up the battery positive ground and see if it charges off the generator. The stickers just say the name of the auto electric shop here in Springfield, Or. . I got the hood off the tractor to remount the VR correctly where it belongs and also got the generator off. Think i'll open it up to check the brushes
 
(quoted from post at 22:15:19 10/28/17)
(quoted from post at 18:42:29 10/28/17) The starter will turn the right direction regardless of battery
polarity. What do the stickers from the shop say?
I don't know of any resistance readings you can use, but you
can measure voltage across the battery terminals.
Measure it not running, then start it and measure it running.
Usually about mid-throttle. It should go up from ~12.4 to ~14.

I guess what I do royse is hook up the battery positive ground and see if it charges off the generator. The stickers just say the name of the auto electric shop here in Springfield, Or. . I got the hood off the tractor to remount the VR correctly where it belongs and also got the generator off. Think i'll open it up to check the brushes
The generator can be polarized to charge in either direction.
To save hassle and confusion, if, IF, it is 12V, I would use Neg ground.
 
(quoted from post at 19:33:23 10/28/17)
(quoted from post at 22:15:19 10/28/17)
(quoted from post at 18:42:29 10/28/17) The starter will turn the right direction regardless of battery
polarity. What do the stickers from the shop say?
I don't know of any resistance readings you can use, but you
can measure voltage across the battery terminals.
Measure it not running, then start it and measure it running.
Usually about mid-throttle. It should go up from ~12.4 to ~14.

I guess what I do royse is hook up the battery positive ground and see if it charges off the generator. The stickers just say the name of the auto electric shop here in Springfield, Or. . I got the hood off the tractor to remount the VR correctly where it belongs and also got the generator off. Think i'll open it up to check the brushes
The generator can be polarized to charge in either direction.
To save hassle and confusion, if, IF, it is 12V, I would use Neg ground.

Ok i'll leave it neg. grd and polarize it that way( Bat. to field right?)

My next question is the VR...I looked for 6 or 12 v markings but don't see any. I get I replace it with a 12 volt
 
I think I would check the battery voltage which should be around 12. Start your tractor then check it. if its working correctly the battery voltage should be higher. I suspect neg ground is fine. just saying
 
(quoted from post at 21:17:49 10/28/17) I think I would check the battery voltage which should be around 12. Start your tractor then check it. if its working correctly the battery voltage should be higher. I suspect neg ground is fine. just saying

The battery voltage was checked to be 12.5 or so with no increase with tractor running. I suspect the VR is bad
 
(quoted from post at 21:17:49 10/28/17) I think I would check the battery voltage which should be around 12. Start your tractor then check it. if its working correctly the battery voltage should be higher. I suspect neg ground is fine. just saying

The battery voltage was checked to be 12.5 or so with no increase with tractor running. I suspect the VR is bad
 
(quoted from post at 21:17:49 10/28/17) I think I would check the battery voltage which should be around 12. Start your tractor then check it. if its working correctly the battery voltage should be higher. I suspect neg ground is fine. just saying

The battery voltage was checked to be 12.5 or so with no increase with tractor running. I suspect the VR is bad
 
you said, "battery to field". If batt to gen field only, all will be well BUT, if you connect batt to VR field terminal and the VR was good, it won't be afterwards!
 
(quoted from post at 09:38:20 10/29/17) you said, "battery to field". If batt to gen field only, all will be well BUT, if you connect batt to VR field terminal and the VR was good, it won't be afterwards!

I opened up the VR and it is real rusty in there...gonna replace it with a for sure 12 volt one. Right now I have the generator aprt checking brushes and bearings...all looks good in there.
 
(quoted from post at 09:46:34 10/29/17)
(quoted from post at 09:38:20 10/29/17) you said, "battery to field". If batt to gen field only, all will be well BUT, if you connect batt to VR field terminal and the VR was good, it won't be afterwards!

I opened up the VR and it is real rusty in there...gonna replace it with a for sure 12 volt one. Right now I have the generator aprt checking brushes and bearings...all looks good in there.

So today I took apart the generator to check brushes and bearings, it is all good to go. At one point in time somebody put on another VR the easy way by mounting it upside down off to the right of the hood..then covered it with duct tape.. I thought who would do such a hokie job, anyway I removed the hood to do it right and remove the old regulator that was still there. I ground off the rivets holding the cover on the old VR. It looked like brand new on the inside. I put that VR back on and wired it up. Everthing working and charging for now
 
(quoted from post at 04:09:31 10/30/17)
My newly purchased 640 shows no charge on the amp meter.

Does it show a discharge (negative charge) when the engine is running, or does it show zero?

Yes Sean I did notice that occasionally...why is that?
 
(quoted from post at 07:13:10 10/30/17)
(quoted from post at 04:09:31 10/30/17)
My newly purchased 640 shows no charge on the amp meter.

Does it show a discharge (negative charge) when the engine is running, or does it show zero?

Yes Sean I did notice that occasionally...why is that?

Also when engine iidling I notice an arcing on contact points but as I increase throttle the arcing goes away and I see a steady charge on the amp gage
 
Showing zero all of the time would indicate that the meter either isn't hooked up properly or isn't functioning properly.
 
(quoted from post at 13:24:29 10/30/17) Showing zero all of the time would indicate that the meter either isn't hooked up properly or isn't functioning properly.
have collected at least 3 different "installation instruction" sheets from conversion kit makers (TISCO, Atlantic...) and they all show the ammeter connected only to measure alternator output and no load current! So, if a fellow followed their instructions, the meter will never show negative reading, short of catastrophic alternator failure & at that point he will likely see smoke before a neg ammeter readout.
 
(quoted from post at 10:59:09 10/30/17)
(quoted from post at 13:24:29 10/30/17) Showing zero all of the time would indicate that the meter either isn't hooked up properly or isn't functioning properly.
have collected at least 3 different "installation instruction" sheets from conversion kit makers (TISCO, Atlantic...) and they all show the ammeter connected only to measure alternator output and no load current! So, if a fellow followed their instructions, the meter will never show negative reading, short of catastrophic alternator failure & at that point he will likely see smoke before a neg ammeter readout.

Thanks for the info JMOR...any chance you could post a link to those wiring diagrams?
 
(quoted from post at 16:12:41 10/31/17)
(quoted from post at 10:59:09 10/30/17)
(quoted from post at 13:24:29 10/30/17) Showing zero all of the time would indicate that the meter either isn't hooked up properly or isn't functioning properly.
have collected at least 3 different "installation instruction" sheets from conversion kit makers (TISCO, Atlantic...) and they all show the ammeter connected only to measure alternator output and no load current! So, if a fellow followed their instructions, the meter will never show negative reading, short of catastrophic alternator failure & at that point he will likely see smoke before a neg ammeter readout.

Thanks for the info JMOR...any chance you could post a link to those wiring diagrams?
n my opinion, those are wrong, so I don't want to propagate wrong. Why do you want them? If you really want them, I could e-mail them to you, but they are really simple in that ammeter is simply in the wire leaving the alternator & connecting to rest of tractor,
 
(quoted from post at 14:35:59 10/31/17)
(quoted from post at 16:12:41 10/31/17)
(quoted from post at 10:59:09 10/30/17)
(quoted from post at 13:24:29 10/30/17) Showing zero all of the time would indicate that the meter either isn't hooked up properly or isn't functioning properly.
have collected at least 3 different "installation instruction" sheets from conversion kit makers (TISCO, Atlantic...) and they all show the ammeter connected only to measure alternator output and no load current! So, if a fellow followed their instructions, the meter will never show negative reading, short of catastrophic alternator failure & at that point he will likely see smoke before a neg ammeter readout.

Thanks for the info JMOR...any chance you could post a link to those wiring diagrams?
n my opinion, those are wrong, so I don't want to propagate wrong. Why do you want them? If you really want them, I could e-mail them to you, but they are really simple in that ammeter is simply in the wire leaving the alternator & connecting to rest of tractor,

JMOR...the wiring on this 640 is cobbled up somewhat and I just need the correct wiring diagram so I can check it ot and rewire as needed. email is [email protected] if you want to send me those, I'd appreciate it

TY
 

with alternator and as it left the factory diagrams:
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