New Guy Needs Help 2005 Z71 will not start

[AZ2005z71]

New guy here, but not new to chevy's, owned several but this problem is the first I've ever encountered like it.
Driving down the dirt road to our house the Tahoe died, thought it was the battery since it would not click over, nothing. Changed the battery, still dead. Turn on the lights, the they dim when trying to start, everything works except the stereo(aftermarket), power windows, door locks.

Lights, ac blower, power seats, gauges light up, there is power.

I've read several threads that point to either the body control module or the passlock systems, where do I start? Some suggested that it might be the ignition but everything else lights and powers up so I think it's something else.

Also where is the BCM, is it in the dash behind the speedometer? And if I replace the BCM does it have to be reset using flash - reflash??? since there is an aftermarket stereo?

Hope this makes sense, need to fix asap since it's my only driver right now.
Thank you for your help.

Tom

 

[retiredsparky]

Get it checked for codes, etc. by an independent shop. Have you serviced the fuel filter lately?

 

[Kenny D]

Sorry, I was thinking the starter, but after I re-read the post I do not know why it is only your starter, radio, PW, and PDL.

 

[retiredsparky]

You are probably right about security system or BCM. Have you checked the fuses under the hood. There are 2 fuses for Body Control and I think 2 more for the ignition. Have you had it checked for any codes. Is the lock symbol flashing on the dash? I don't know where the BCM is located, anybody know?