I am working on a 2006 Impala with 119,000 miles on it and it drains the battery over about a 2 month period. The theft light never blinks i have noticed and the ignition beeper is real quiet also. The ignition doesn't lock when the key is out and you turn the steering wheel and also the ignition will not go back to accessories. It has a very strong draw on battery when I disconnect the negative post and put meter on it. I have tried pulling all the fuses and relays out one at a time to see if the draw goes down but nothing. I have also disconnected the bcm, the cluster and the radio because I know they are problems with these models but still it doesn't change the draw on meter. I don't have a tech 2 to scan anything but I do have a Genisys scanner. Any help would be appreciated because it is very aggravating. Thanks!

 

If you've actually pulled/removed "all" the fuses/load, then there is only two things left.

1) Battery Cable (positive slightly shorted-corrosion)

2) Short in your Starter.

But, beyond that, you need to turn everything on, and see if your Alternator is putting out 14.5 vdc, and you really need to get that Ign Sw replaced. Then, take apart every ground wire you got, scrub/clean tighten !

 

That's what I plan on doing next is changing out the electrical side of the ignition switch but I have to wait for the customer to bring it back to me first, they keep driving it and just jump it off everytime they start it which is crazy.