"pulsating lights" - Third Generation F-Body Message Boards

UKREADER · 03-18-2003, 03:52 PM

Hello everyone,

I hope someone can help me with the following.

I am in the UK and have just purchased a 1984 Trans am with a 5.7 ltr engine.

I have a problem in that when you have the engine running and the door open or indeed the lights on they are "pulsing"
I have had the alternator checked and no problem. New battery and now am considering my next course of action.

I had the same problem on my 1989 GMC Explorer conversion van. I had everything changed to no avail and finally assumed it was the draw from the tv / vcd player.

However the Trans am has none of these items and the problem is the same if not worse.

Another thing the interior volt meter shows just over 14 volts.

Hope you can help

Thks

Ray

spitz74 · 03-18-2003, 04:28 PM

If the lights only pulse with the door open, try changing the switch that tells your car the door is open to turn the interior lights on. It's the little pushbutton switch by your door hinges. They are very inexpensive and easy to replace.

UKREADER · 03-18-2003, 04:33 PM

Thanks for that. I'm sorry I forgot to mention the headlights and all exterior lights pulse as well when the engine is running
Very annoying especially when driving at night!!!

Ray

Jza · 03-18-2003, 05:42 PM

It's possible something's drawing some current somewhere then. You can start isolating it by pulling a fuse at a time while it's doing that (don't pull critical fuses, though, obviously) until it stops. That can help you find out what circuit it's on at least.

82camaro · 03-19-2003, 05:10 PM

Sounds like the voltage regulator in the alternator is on it's way out. Sure the alternator is charging(when you had it tested), but is the voltage constant. Or is it going up and down, up and down. When mine did that, a new voltage regulator in the alternator fixed it up(put brushes and bearings in it while it was apart).