Electrical Problem?

woyster_00z71 · September 18, 2003

Hey guys, I think I have a problem brewing and I would like your opinions on what you think it is and how to go about fixing it.

I got home last night at about 9PM and parked the Tahoe in the driveway. This morning at 6:10AM I started it up and noticed that the radio was off. I know for a fact that it was on when I turned the truck off because I always leave the radio on. Anyway, I turned it on and began driving to work. Not long after that I noticed that the clock on the radio was 4 hours fast...it read 10 instead of 6. All I can figure is that I lost power to the radio and it reset the clock. However, all my station presets were still in memory. At the first stop light (traffic inhibitor) that I came to I turned on my interior lights to reset the clock. I noticed that the lights were rapidly dimming and then coming back. They weren't going completely dim, just a little but it was noticable.

So, what do you think it is? My first thought was battery but the truck started fine this morning and the alternator seems to be charging as normal. I popped the hood once I got to work and the battery cables look alright with the positive battery terminal bolt a little rusted. I then turned off the Tahoe and it would restart with no problems.

I'm stumped. Can anyone figure this out?

Thanks in advance,

B.J.

toddgotfish · September 18, 2003

keep an eye on your volt gauge

as well as the alternator

next time you see the lights dimming be sure to

look down at you gauge

sounds like the regulator in the alt may be going bad

gmcsid · September 19, 2003

Check your battery cables, especially the positive one, for corrosion and loosness.

cyclejerk · September 19, 2003

Possibly the "brushes" inside the alternator are sticking and NOT making good contact to the shaft that generates the electricity?????

I had a car do the same thing before. The guy I took it to used a hammer to wack the alternator and the problem was cured instantly.

We did change the alternator because he said that it would more than likely do it again very soon. He said not to wack it to hard but just enough to create a nice shock/vibration to it so as to free up the dirty/rusted/coroded brushes.

My 2 cents.

Shaners · September 19, 2003

There is a TSB about this... If you are still under warranty then your dealer will take care of it for you. Mine has done the same thing several times, and I will mention it to the dealer the next time I'm in for service...

Sorry but I don't have the TSB number, but I gaurantee you that it is a known problem....

The dealer will replace the radio for you.

99silveradoz71 · September 19, 2003

My past experience with 2 dying vehicles tells me it sounds like the alternator. At least that's what the dimming lights were on my 85 Dodge 600 and my bro's 96 Regal.

woyster_00z71 · September 19, 2003

Shaners: This is a radio problem? As long as it isn't an electrical problem (alternator, battery, etc) I can live with it. I don't like the stock radio setup anyway and am saving up to put in my own system. So, as long as it is only a radio problem I'm not too worried about it.

My Tahoe has over 60,000 miles on it and is out of the original factory warranty. I do have a GM extended warranty but I would guess that wouldn't cover the radio anyway.

Thanks Shaners!

B.J.

Shaners · September 19, 2003

As far as the clock goes, it is a radio problem...

My headlights dim noticably when I come to a stop sometimes and then they brighten right back up. I know other people with GM trucks that have lights that do the same thing, so I guess that is "normal".