Lights flickering/pulsating....

[Chuckk1]

I started noticing this about 6 months ago. I thought I was seeing things at first, but upon starting engine at night, I noticed the interior lights 'pulsating' very mildly as if the voltage was rising and falling several volts at a rate of maybe 3 cycles per second. It usually goes away after a few minutes....sometimes not. The 'pulse rate' is not dependent on engine rpm's. Even the headlights 'pulse' in time with the interior lights, so it is obviously the entire electrical system being affected. I suspected the alternator or voltage regulator (if there is one on this car), but everything has kept working. It's a bit disorienting, especially on a dark road at night.

[Indy8]

Disconnect battery and clean all contact points. I'd use a little anti-corrosion gel on terminals. Also, check the engine ground strap just above the alternator(next to serp. belt). If this doesn't cure it, I'd take it to a GOOD shop that can check the entire system. This sounds like an isolated electrical/charging problem that shouldn't require specialized dealer tools, so why pay the big $. I wouldn't attempt any electrical repairs on my own. It's not worth the consequences.

[bustedratchet]

I know a guy his lights flickered even with the car off. Found out it was the multifunction switch.

[RorthStar]

I had the same problem with a 96 Blazer I used to have....sounds like the exact same problem you have. My problem was the alternator regulator. Unfortunately, on our new fangled General Motors cars, the regulator is built in to the alternator, usually requiring replacement of the entire alternator. Hope this helps!

ps, a new alternator for the aurora is averaged around 140, don't let the stealership rip you off....gm part number is 10463689, and the list price at gmpartsdirect.com is 126.13....later!

[Indy8]

What is the constant voltage output in the engine functions(on the DIC) at idle RPM? If it's fluctuating, it probably is the built-in regulator. I heard an alternator job requires radiator and fan removal to get it out. I'm replacing my radiator now and it looks to be true.

[scruff]

Indy8, can you give some details on replacing your radiator? I have a 97 also that has a crack in the plastic piece where the hose comes into the top of the radiator. I've read about the seal tabs, but I'd like to do it right...but not for $525 like the stealership is asking.

[Indy8]

I'll post a new thread on it later today, okay?

[Pullcord]

I had a remanufactured alternator installed about 18 months ago...and I believe this to be the cause of the flickering. I've just learned that the regulator is part of the alternator itself, and that must be the problem. I can live with it, but is there any danger when the battery voltage shoots up to 18 volts? I'm getting fluctuations anywhere between 12.7 and 18 on the display. The normal is usually 14.7 to 15.2 for my Aurora. But when it jumps to 18, the airbag light comes on. My alternator charge light has been on for about 5 months now, but thebattery has never ever run down.

[1996 Aurora]

4 months ago my fog lights and head lights would flicker when vehicle was off and the Delay lights were on. Now my fog lights stopped working and my low beams stopped working. I replaced new headlight bulbs on my 96 aurora and same problem, my low beams dont work so I have 2 drive with my high lights. Anyone having these symptoms?