Alternator resistor for 60's GM

[Texas Diesel]

I would appreciate help in locating a resistor or it's value/wattage

for a three wire GM alternator. The original resistor is toast. It is on a tractor and was transplanted so cany look it up at Autozone.



These alternators have three wires, ground, ignition, and battery.



They use the difference in voltage between ignition and battery to determine the charge rate (actually the field current). There is a resistor in the ignition lead, it 'was' 3/8" on a side and 1. 5" long.



Any help/information/suggestions appreciated.

 

[bmoeller]

My boss has an industrial air compressor. Has Ford engine(same one used in the 901 Ford tractor) that uses something similar. I think it was 2 ohms, but not 100% sure. It's been a year or two since I had to replace it. Got it from either NAPA or Big A (it's now a Carquest). I can check it tomorrow if you want. I'll see if I can still read the P/N also.

 

[Texas Diesel]

That would be fantastic!!



Thanks!!



-- email address removed --

 

[bmoeller]

I looked at it this afternoon. The only thing that was on it was- D. Pat. No. 254186. Made in Mexico.



I checked it with my digital multimeter. Didn't gain anything with it. There was only . 2volt drop across it, and the resistance was either to high or to low to get a reading as though it was open. I did have continuity through it. It may have a diode in it too, which I forgot to check for that.



If you don't find one at an auto parts store, try a place that rebuilds starters and alternators.



Good luck.

 

[Texas Diesel]

Thanks for trying

 

[bmoeller]

Have you had any luck finding the part? It dawned on me a few minutes ago that I think I wrote the p/n's down under one of the doors on the compressor. If you still need them, I will look when I get to work tomorrow to see if I did.

 

[Texas Diesel]

No luck yet This is one of those things I have to walk in and ask for, too easy to say "we dont have it" on the phone.



A P/N would be great.

 

[TowPro]

Wipped out the old books!

Well I got out the old book, just for you.



In the GM section all it shows is "resistance wire", nowhere does it show a value.



Looking at this picture the resister wire is parallel with the charge indicator light.



Now on the next section is the Ford Alternator.

It shows dam near the same wire diagram, only they have a 15 Ohm resistor across the charge indicator light (parallel).



I guess thats a good starting point.

 

[bmoeller]

No luck I'm afraid. Had #'s for the points/condensor and the distributor, but not the resistor. I think the box must've gotten tossed before I wrote it down.

 

[Texas Diesel]

Thanks for trying, I've got a good start

 

[bmoeller]

Your welcome.

 

[Eric Kahn]

You might want to look into converting to a newer single wire alternator with a built in regulator

your 3 wire alternator should have a voltage reulator mounted somewhere else that controls the output of the alternator

 

[TowPro]

I agree. If you need assistance with the wiring, let me know, I can copy it out of the book for you.

Originally posted by Eric Kahn

You might want to look into converting to a newer single wire alternator with a built in regulator

your 3 wire alternator should have a voltage reulator mounted somewhere else that controls the output of the alternator

 

[Scot]

The one on my Delco internal regulator ('70's model GM) alternator measures out at 200 ohms. The color bands have faded away.