Generator light.

Hi Everyone,
The Generator light in my 71 stays on whenever the engiine is running, it is charging fine . It never really bothered me , Its been like that for years, but now the car is restored I would like to fix it.
The alternator is new, as is the voltage reg, and the starter is rebuilt. Any ideas appreciated.
Thanks, Adam.

 

adam,is the light on all the time(key out of ign)just when running,bright or dim,brightness change with RPM,did it do this SAME thing with old alternator?71 wiring harness?71 had remote regulator,72 had built in,alt wiring in harness is different.:Smarty:

 

Adam, last time I had a similar situation I found that the little plug-in wire was broken clean through. In my case the light even stayed on when car was totally off with the key out.

 

Hi Guys ,
The light is only on when the car is running.
It stays the same intensity all the time,It was the sane before i did the resto , old alt. and remote voltage regulator, the wiring seems good.
Weird Eh?
Adam,

 

Adam,
I had the same thing happen to me and I found my plug for the voltage regulator wasn't plugged in correctly and the generator light was constantly on when running. If all parts are new consisting of the charging system I would check all the wiring to make sure everything is okay. Was all the wiring replaced when restoring your car?

Rob

 

check the "R" wire,blue if i remember right,from the back of the alt to the light circuit.make sure it is NOT grounded somehow(worn insulation).the only way the light will come on is if the light circuit(pos w/ key on)finds a grond to complete the circuit. no ground,you have a pos to pos circuit,and no light!also,have a reputable electrical rebuilder check both components off the car. not the local "parts store". i have run into a larger number of transistorized regulators that are defective in the last couple of years. if yours is transistorized,i recomend finding the points style,and running it.:Smarty:

 

Thanks for the help guys,
I guess I have to go through the wiring again, it is the only thing
not replaced, just cleaned and repaired as needed.
Adam.

 

Did we ever find out what this problem was caused by. I have the same problem.

Steve

 

Hi Steve,
No, I did not fine the problem yet. I put the car in storage before I had a chance to look,had a lot of grief with it last summer, not vey motivated. I will be getting it back at the end of March and I will be back at it then . I will let you know.
Adam.

 

Hey Guys
I ran into the same problem on my 70 GS, I took almost the whole engine harness apart before I found the the ground from the battery was loose ou: DUH! Once i tightened the ground to the block the light went out. I hope yours is that simple!

 

I know why. It's the same reason the light is supposed to come on half bright when the key is in the "accy" position. Current is going into the bulb on one side, and not another. When everything is fine, the bulb sees the same current from both sides and goes off. If the car isn't running, it should come on half bright- only 7 volts. It mat mean the charging system is faulty.
It would also indicate a broken wire or screwy fuse, I suppose.


So sayeth the Chassis Manual:


"Before the engine is started, the generator light should glow at about 1/2 brightness. This is because the voltage in the circuit is at about 12 volts, but the voltage at the "4" terminal [voltage regulator] after the light is about 5 volts. this makes the effective voltage across the generator light approximately 7 volts for about 1/2 brightness.

After the engine is started the voltage put out by the generator immediately closes the field relay. This causes battery voltage from the "3" terminal [v.r.] to be present at the "4" terminal [v.r.] Since battery voltage is present on both sides of the generator light, the light goes out."

Praise be to the Chassis manual, combustion without end,
Amen

basically the voltage needs to be the same from the ignition switch and the volatge regulator. It's sort of like having an Idiot light that can count to three instead of only two. Very clever, these Buick idiot lights.

This happened to me too, BTW. :laugh:

 

I am getting there

What I found out is this. I took off my voltage regulator cover and adjusted the phillips headed screw. When I turn it up so the mechanical switch made contact the light went off. The switch would move mechanicaly on and off. Doing this turned the Gen light on and off.

My problem is I cannot turn the screw far enough to keep the switch on.

Do I want the switch to stay on?

I am a bit confused here but I think I am getting somewere. Where, I have no idea!

Any help is appreciated