regulator relay

[baker4106]

I own a 1961 GM PD4106 and it has a relay in line with the regulator.   None of my wiring diagrams have this relay.   It controls the battery power to the regulator and is correct as it works.   Does anyone have a wiring diagram for this setup?   Larry 4106

[pvcces]

If it is the sensing relay that you are talking about, I might be able to help. We found ourselves in the same position as you are in, and one of the busnuts from Alaska had the diagram and sent us a copy.

What I don't know for sure is whether you are talking about the sensing relay, whose job it is to detect that the engine is running and furnish power to the regulator so that full power becomes available. These relays fail fairly often and prevent the charging system from working when they do.

IIRC, there is a small amount of current furnished to the generator field that serves to get the connecting process started.

Let me know if I have the right relay.

Tom Caffrey

[baker4106]

Sounds like you are right.   I replaced the relay to get the charging system working again but I would like the wiring diagram.   Larry 4106

[Hartley]

Yep.. That's the relay on GM's that prevent the voltage regulator from
drawing power when the engine is off. Without it either the alternator doesn't
work or the batteries will go dead from the regulator being hot and sending power t the alternator fields...

But, You knew that...

[akbusguy2000]

The generator sensing relay was not incorporated in the very early 4106's and that's why it doesn't appear in the original wiring diagrams.  But it does show up in the supplement X-6414.  I'd recommend you get a copy of the supplement if you can.

This relay works in conjunction with the Starter control relay to prevent starter engagement while the generator is working, and vice versa.  The generator sensing relay also controls the "not gen" light and a few other odd functions, depending on the special equipment, if any.  It's not a terribly complex system but a replacement for the starter control relay is next to impossible to find, and mine was determined to have an intermittent open coil.  I ended up replacing both of my relays with magnetic switches, using the procedures manuel published by Coach Intormation Network.  The change did away with all the starter and generator problems I had been having, including a nagging one with pulsating lights.

Here's a link to the manuels:

http://www.coachinfo.com/Manuals/Coach/GMC/4106.html

tg