New to me 641 - Electrical System Question

00_Green

Member
I recently purchased a 1959 641 that has seen better days. I've cleaned the carb, was able to unstick the clutch, and I'm ready to tackle the electrical system.
The tractor had been sitting so I charged the battery and it cranks and runs but is not charging.
What I know is that a 12v battery is installed and hooked up negative ground, the coil is 12v, and it has a generator.
Does this sound like a stock configuration for the year and model and if so where can I find a wiring diagram.
The harness has a few splices and terminal ends in poor condition, a dash mounted stater switch is installed. I don't know if the generator and regulator are actually 12v.
I don't mind investing in the tractor to have a reliable electrical system. My first choice would be to troubleshoot what I have and repair it, it may just be a open or incorrect connection.
It all else fails I could install a 12v conversion using a new harness but again my first choice would be to fix what I have rather than just throw cash at it.
 
(quoted from post at 08:54:56 07/17/19) I recently purchased a 1959 641 that has seen better days. I've cleaned the carb, was able to unstick the clutch, and I'm ready to tackle the electrical system.
The tractor had been sitting so I charged the battery and it cranks and runs but is not charging.
What I know is that a 12v battery is installed and hooked up negative ground, the coil is 12v, and it has a generator.
Does this sound like a stock configuration for the year and model and if so where can I find a wiring diagram.
The harness has a few splices and terminal ends in poor condition, a dash mounted stater switch is installed. I don't know if the generator and regulator are actually 12v.
I don't mind investing in the tractor to have a reliable electrical system. My first choice would be to troubleshoot what I have and repair it, it may just be a open or incorrect connection.
It all else fails I could install a 12v conversion using a new harness but again my first choice would be to fix what I have rather than just throw cash at it.
iesel from factory was 12v gen & VR, neg gnd, but gasoline was 6v gen & VR , pos gnd.
 
Thats what I was starting to suspect when I couldn't locate a diagram. I've attached pictures of the gen and VR, neither has numbers on them. Any way to know if they are are 12v or 6v?
In the middle picture, I suspect thats a broken terminal block?
cvphoto29917.jpg


cvphoto29918.jpg


cvphoto29919.jpg
 
The factory 12v gen had cooling slot on bottom of barrel close to read & 6v had no slot. There has been about 60 years for unknown changes to have been made. Simplest way I have found to try to determine 6v/12v on small generators such as this is ti measure field coil resistance. 6v fields around 2 to 4 Ohms and 12v about twice that. If as from factory, it will be Type-B system where one end of fields tied to case and other to Field terminal on barrel. Sometimes, but for sure not always, the VR will have voltage marked on bottom of it.
 
(quoted from post at 10:34:44 07/17/19) The cooling slot on a 12V generator looks too much like the entrance to a beehive!
<img src="https://www.yesterdaystractors.com/cvphotos/cvphoto29928.jpg">
rushes don't look too worn! gotta look for positives, you know. :)
 
Below diagrams may help. Looks like you need to clean up and check all of your connections.


<img src =https://i.postimg.cc/G2MZ37fH/Ford-Electrical-Resized.jpg>
 
Andy, the harness does look terrible, splices, wire nuts, questionable terminal ends and corrosion. . If I knew my components were correct and functional I would identify a proper replacement harness.
I did remove the VR and 12v was stamped on the base. The resistance of the gen was 3 ohms between F and G, 6 ohms between A and G.

Looking at the wiring diagrams, the terminal block is only a landing point and the two posts are not connected.
My broken block shouldn't be creating any problems.

Thanks for the diagrams!!!!! What manual are those from, I still need to buy one.
 
The diagrams are from "Ford Service Manual Tractor Series 600, 700, 800, 900, 501, 601, 701, 801, 901, 1801, 2000, and 4000 1954 - 1964". Number is 400060090. Very good manual if you can find one. Mine is falling to pieces from use.
 

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