Electrical Problems On Chevy Tahoe

My wife has an '05 Tahoe with over 50,000 miles. When it is put in gear and starts to move the auto door locks engage and you hear a loud buzzing noise. If you start the car in reverse, back out, and then switch to drive you hear this sound roughly half the time. On a recent long trip she noticed that when she stopped for gas the car did not have enough power to start, but on her return if shed did not use the cruise control, cd, or radio it didn’t drain the battery as much. Any suggestions or ideas?

I really don’t much of an idea, other than to check the charging system. HOWEVER, my son’s experience with a 2007 Tahoe with a flawed charging system suggests that you should check with a Dealer to see if they have some kind of Technical Service Bulletin or maybe even a recall about your year Tahoe.

On the '07 there was something – symptoms like battery drain – that Chevy had the Dealer fix. There is a little more info in the saga here: http://community.cartalk.com/posts/list/1389011.page;jsessionid=4708842085DEB83E32772A5E7F659718. Maybe somebody else on this forum can point you to TSBs or whatever.

All electrical problems start at the battery,how is yours including connections at the battery?

If the battery in your wife’s Tahoe is original I suggest you tell her to drive to an auto parts store and have the battery tested. It may be time for a new one.

They can test the charging system at the same time to make sure that’s working correctly.

The battery is not the original, but I will get the battery and the charging system checked at a nearby store. Any one have any thoughts on the buzzing noise?

Again, no real ideas. But MAYBE it’s caused by low voltage from the battery and the charging system, and if you get that fixed then the buzz will go away. And then you can can convince yourself not to worry about it any more :>)

Anyhow, address the charging system first, then see if you still have the buzz.

Really low battery voltage can cause the audio amps (even the small one in the radio) to buzz or make pulsing noises.