Is my Envoy possessed?

I sure hope someone out there can help! I have had my 2004 Envoy XL for almost 2 years I have put over 40,000 miles on it since I purchased it. This truck is a mess, it has intermittent problems that all seem electrical.

Issues:
won't start (dead battery)
A/C won't blow cold
HVAC stays on when car is off
Radio won't come on
tail gate won't unlock
drivers side keyless entry won't work
rear windshield wiper won't come on
lights won't come on
all gauges are inaccurate (no gas when gas, 120mph when im going 30mph)
check engine light on and off
Rear AC controls no longer work at all
and half dash lights aren't working

If I disconnect my battery and then reconnect when i'm ready to drive everything is fine, this also turns off HVAC, but even removing fuses wasn't helping.. we checked all the relays and fuses.. nothing is bad


I have replaced the battery twice, my alternator tests fine, half the time when I take it to get it checked out there are no codes or no codes specific.

I have heard a lot about the BCM, but have also heard about a grounding issue.

Any suggestions? Im a single mom and don't have the money to waste to take it to the dealer if it is something I could have done by a friend..

PLEASE HELP!!!:crying:

Unless your friend is intimately familiar with the electronics in this truck you need the dealer to get involved, there and many and seperate causes for some of the problems, speedo head needs repair, possible ign switch, possible bcm issues, the codes and history need to be read and so on.

Hi would like to tell you what worked for me the rear latch harness that passes from the body to the lift gate can wear the wires thru this can be noticed underneath the headliner the wire that had worn thru on mine was live all the time resulting in a battery drain.the wire goes to the rear gate module which controls the rear wiper ,fobs ,rear hatch lock and defogger

also note it may have damaged my rear hatch module I am going to see if they can reprogram this module I might have to install a new one and have it programed in

Put a new fuse in the #19 rear seat fuse block rear latch module fuse and every thing came back to life front pwr seat , heated seats, rr wipers fobs, and that anyoying clicking from my rr heater . extended version