The Fordson Tractor Pages Forum

Can anyone point me to a wiring schematic for a 12V alternator conversion on a PM? My uncle (the previous owner),bought it this way, and it was not properly done. It came with the original 12V generator in a box of parts when he bought it, but in his infinite wisdom, he tossed it thinking it was useless. Now I need to get the electrical sorted out over the winter in my garage, and a good diagram would be very helpful. Thanks guys!

Check oput this thread which addresses that issue:

http://www.fordsontractorpages.nl/phpbb ... tor#p29235

Thanks! That is helpful in identifying the circuits, but I have a Delco style alternator. What they call a 1 wire I think. Perhaps the picture will help.

May be some help: http://www.fordsontractorpages.nl/phpbb ... 43&p=27148

This should do the job:

So this is a 1 wire alternator that I have?

See here: http://bob_skelly.home.comcast.net/~bob_skelly/alternator_conversion/wiring_alternator1.html
Looks like with a 1-wire Delco, you won't have a warning light.

As long as you have a working ammeter, would you need a warning light?

He has a PM which does have a warning light.

The battery switch side of either the warning light or the ammeter should work just fine.

Thanks fellas, that's exactly the info I needed!

You can not tell whether your alternator is a 'one wire' type from the photo. It is actually pretty unlikely as the one wire types generally have a rubber plug over the two connectors on the side. Whether it is or not, it is not connected properly. The post on the back side is always connected to the battery, as this is the main output terminal. Of course, if you use an ammeter it connects to the battery through the ammeter. This should be a heavy gauge wire, generally about 10 AWG and should be hot at all times, not going through any switches. A one wire alternator uses no other connections. One of the side connections is for voltage sensing and it is sometimes connected to the output terminal as yours is. The other side connection is for the indicator light and also provides power through the indicator light at startup to 'turn-on' the alternator until it produces enough power to operate itself. This lead should not be hot when the engine is not running or it will drain the battery. It should turn on and off with the ignition switch, as it will if it connects to an indicator lamp. The alternator will not start charging until very high speed if this connection is not in place or if the indicator bulb is burned out. There are lots of variations in how the connections are actually made and used. There are lots of diagrams and discussionss on the internet.

That's what I figured Don, I've got it now. This is how it was wired when we got it from my Uncle a few years ago. The owner before him had wired it this way, thinking he was a mechanic. I'll get it sorted out when I bring the old girl home in fall.

It is not wired right. The lug nut on the rear should go to the battery side of the soleinoid with a 10 gage wire. The larger wire out of the plug should go the same lug. From the factory, the GM vehicles had a piece or fuseable link wire in case of a short in the alt. The smaller wire in the plug goes to the light which will light when the key is on and go out when it is charging.

Thanks Dave!