Morning all,
I have a 1980 PU running the 55amp alternator and regulator. I have started frying regulators. I had the alternator checked out and its coming back good, checked by two different shops, and I have started chasing wires in the wiring harness for shorts but haven't found anything prior to the fire wall that would suggest a short. I checked the voltage drop, less than 1/2 a volt and the battery voltage return pin on the harness was showing the correct voltage. I also replaced the idiot light relay, but I'm not certain I found an appropriate replacement. At this point I will need to replace another regulator and the battery as its now fubar'd.

So few questions:
Can I wire in newer standard relay for the idiot light? Should it be N.O. or N.C.?

What am I missing on testing the charging system?

One of the guys at my parts store suggested moving to a GM 1-wire system, Are there any good write up on making that conversion?

 

The gm 1 wire is really a easy way to go. With your regulator make sure you have the right amount of pins cause if I remember correctly there were 5 wire systems and 6 wire systems. Don't remember if the plugs were the same.

 

You are correct, there are 5 pin (55amp) and 6 pin (40amp) systems, I have the 5 pin (55amp) system. The second shop I had check the alternator verified I was using the correct regulator and walked my through doing the voltage drop and battery return tests.