All Lights are Pulsating

[pgnavy]

What do you guys think....ALL lights in my 87 V1500 have a very slight but noticeable pulsation; headlights, dome light, etc. The pulsing does not go fast or slower as I rev the engine, its just a constant slow rolling pulse. The battery is 12 months old and cranks the engine very well, clean terminals, and I completely rebuilt the alternator last year with many new internal electrical parts and bearings. Any ideas for me to start checking? This is not a daily driver, but i use it a few times a month, and it stays garaged.
thx in advance. Paul

 

[75gmck25]

Maybe that's the DISCO option code.

Bruce

 

[Westislander]

Terminal corrosion?

 

[Shorty81]

....also you have to wear high heel shoes and wide collared silk shirts half unbuttoned to drive it...

 

[Snoots]

Sounds like one diode on one phase of the alternator has gone bye-bye.

 

[Blue Ox]

Does it do it when the engine is not running? It's probably the voltage regulator. I've seen it once before on a Delco on a 4 cyl. Changed the regulator and the oscillation went away.

 

[pgnavy]

OK, I am buying the Delco 12SI alternator rebuild kit (again) that includes the diode trio and the regulator....$24. Will give these a try. thx Paul