Electirical problems with my Tahoe

[ATC-Eric]

Hey everyone,

I just got a 1999 Chevy Tahoe. It came with a problem. Everything electrical pulsates. The dash lights, the headlights, even the volt gauge slightly moves. They dont turn off, they just dim and brighten at a fairly regular rate. I had the battery checked, the reading was 12.8 volts from the battery, and 14.6 from the alternator. the guy at O'reilys said that they were both fine.

Does anyone have any suggestions?

[smokinwrench]

Does it give a constant 14.6 output or does it fluctuate? I would start checking grounds. First place I would check is the connections on the starter.

[Pistonhead]

Yes the starter connections are very prone to becoming loose.

[darrel632]

Start looking at AC units, heaters, etc as soon as you start blowing switches and resistors you know where the problem is, if it just started with the weather we've been having look at wiring in / around the front wheels or areas where ice builds up in the under carraige thats where your issues possibly could be as well

[grundlegrabber]

Check all your grounds for tightness/corrosion. You will need a service manual/wiring diagram for the ground locations, there are probably quite a few. If they all check out, I'd look at the alternator. Sometimes, even though they seem to be charging there can be other problems such as AC ripple (where the current is not completely converted to DC) which will cause trouble.