I have a 70's 400 in my 69 firebird, more recently I noticed when running that the lights are pulsing. I tested the Alternator and it is good, my guess now is that the voltage regulator is slowly dying. I plan on replacing it but was wondering if anyone else had any other suggestions of what could cause this issue. I also thought it could be an internal ground in the dash assembly as the car does not have the stock radio (just a vacant space now) and if I have the hazard lights on and press the brakes at the same time the hazards don't flash they just stay on. Any help and suggestions would be greatly appreciated
Thanks for that update did not know that was standard but makes sense, and it stays at 14v charging which made me think it has to be the voltage regulator
Do yourself a favor a pick up a solid state regulator, I went through 3 parts store mechanical regulators before I got fed up and got a solid state unit. You can find them on Ebay and probably Amazon as well.
14.2 volts dead steady, loaded unloaded, idle or cruise.
If the lights still pulse, you have a bad alternator.