Volt gauge fluctuation

[BigEd78]

My 2001 LS was making a chirping noise so my brother helped me change the serpentine belt. The next day all seemed better until I went to the gas station, filled up and a few seconds later heading to exit the gas station I stalled out.

Now I'm noticing my battery gauge is going from 14 volts down to around 11 or 12 when I'm at a stop light but goes back up to 14 a couple seconds later.

Has anyone had a similar problem? I don't want to start throwing parts and $$ at this without some direction..thanks

 

[NavyDoc8404]

First thing I would do is get a free electrical charging test. Could be just a cell or two going bad in the battery, need a new alternator or just a loose contention.

Sent from me to you via my phone.

 

[RED TAHOE LS]

I think I would make sure you have he correct belt, if you only had a chirping noise prior to the belt change. If the belt is slipping, your alternator will not produce correct voltage @ idle. JMHO, and good luck.
David g............