I have a 07 Monte LS, and for a while now I have been dealing with my Battery and Alternator, So While driving on the highway my battery light comes on and when I park and come back to my car it needs a jump. This has been going on for over a year, So I have gone through countless Alternator from Oreilly's and Battery from Advance auto, So after changing those two things so many times, I came to this forum and seen someone say a BCM so I ordered one from Rockauto.com had this shop put it on and program it and 2 days later same thing, So I take it back to get a diagnostic done, and they tell me it's the battery and alternator, So this time I go and buy a Alternator from the dealer and I got a new battery, and after 2 days driving my car did the same thing, battery light came on driving down the highway, then I needed a Jump once the engine was shut off, can anyone point me in the right direction, should I just have the dealer look at this,

 

Welcome to the MCF,
Sorry to read about the problem that you are having.. Did any of the companies that you dealt with have a warranty on what you purchased or had installed .

Sounds like you have a major drain on your electrical system ?
I would return it to the ones that worked on your Monte & demand that they recheck it (without cost).

Also, check back to see what our expert tech member's post when they read your thread problem(s).

Wish you good luck & a good starting Chevy Monte Carlo 4-Sure

 

Sounds like a wiring issue. Check the alt ground and make sure it's got good ground.

 

Ok thanks, I will try that with the Alt Ground

 

You have a parasitic drain - a circuit that is drawing power when the engine is off. If you have the time and patience you can locate the circuit by monitoring the battery voltage with an LED meter and pulling fuses 1 by 1. When you pull a fuse and see an increase of voltage at the battery you have found the bad circuit. From there the circuit needs to be diagnosed.


If you don't have the time or patience a reputable shop can do this for you, I'm surprised that neither the first shop or the dealer conducted this test.


Good Luck