hi im new to this just have a question. my 1997 gmc sierra pickup has pulsating lights, was wondering if this is the voltage regulator or if any1 has any advise. ty!!!

 

Do you have a big stereo system?

 

i did upgrade the factory stereo to a cd player, got it from crutchfield, and it just plugged in, but no amp, or speaker upgrades

 

That wouldn't do it. When do they pulsate? I would definitely have the alternator and battery checked. Most auto parts stores will check them for free or if you have a battery specialty store they will also check them. Let us know what you find.

 

yes, they pulsate the minute the truck starts and the voltage meter jumps all around from 13 to 16, the battery is new but the alt is old so im guessing its the alt ty very much for ur time

 

Well i replaced the alt, and the pulsating lights went away. Thank you for the advise!!

 

Excellent...glad it worked out!