I have a 1972 cutlass and I noticed my interior lights would pulse when I rev the engine. I had the car out the other night and all the lights, Dash and head lights did this. Lights seem to dim a idle also.
I assumed the voltage regulator or alternator is bad, but I'm not sure if I have a alternator with the regulator in it or if the regulator is what I'm seeing on the firewall. What I see on the firewall sure looks like the regulator, but I've been told the alternator has the regulator in it. I know this is a dump question, but can it be either way. Thanks Barb.

 

From the factory your car came with an external regulator mounted on the firewall. It should have a four wire connector with brown, white, red, and blue wires. The pulsing could be the regulator, alternator brushes, or a bad ground or missing ground strap.

 

My lights pulsed like that when the external mechanical regulator was used. It stopped when i switched the mechanical reg to an electronic one.

 

there is an adjustment that can be performed to reduce/eliminate the pulsing.
it involves the thumb screw inside the regulator. myself, i went 12si, then cs130 and never looked back.


bill

 

I agree, the later alternators are well worth the trouble to install. Not that its much trouble to install one.

 

OK! Thanks, As long as I'm not damaging anything running it this way. I'll take it in to my local shop, this looks like more than I can handle.
Thanks again guys, best source for information is you. Barb.