Hello, new here.
My 2010 suburban has had a long existing problem with the starting issues for some time. I corrected the trouble by replacing the negative cable from dealer. Problem went away for about 6 months when I dicovered the "dome light" push button had been re engauged so it would work like normal whan doors open. Wife must have done it
, anyway when the dome light push button is enguaged it has a parasitic drain on the battery. If I leave it off, I never have starting trouble.
OK back to A/C, Had to leave the truck parked two days at the ranch and drove pickup to town. When I returned and was ready to drive the suburban back home it just "clicked" and I knew what that sound ment so I hooked up the trickle charger for about 30 minutes and it started and charged at 14 volts approx like normal. I looked down at the outside temp on dash and it said 55 degrees. Hot air was coming out of all vents even though it was on "auto" for 60 degrees. I pulled the BCM fuse and left it out for about 5 minutes and replaced it and found 55 degrees on outside temp again (even though it was 98 degrees outside) I had cold air on driver side but scalding hot air on passenger side!
I had to drive the 120 miles back home with just cold air on driver side and vents closed on passenger side and widow barely cracked open so I would not have a heat stroke.
I figured it would somehow reset itself after two days but no way, still same hot air on passenger side. I try'd all settings I could and now have cold air in rear passenger seats and back but NOT passenger side front.
I have discovered this condition only happens when the battery is down too low to start the engine, it is scary sometimes to see the volt meter flucuate between 12.8 and 14.6 volts and was told the ECM controls the charge voltage only when needed.
Does the BCM need a new program update or something?
I know I am not the only person who has had this problem and looking for a little help before resorting to the good ol dealership.
Thank for listening.
J W
My 2010 suburban has had a long existing problem with the starting issues for some time. I corrected the trouble by replacing the negative cable from dealer. Problem went away for about 6 months when I dicovered the "dome light" push button had been re engauged so it would work like normal whan doors open. Wife must have done it

OK back to A/C, Had to leave the truck parked two days at the ranch and drove pickup to town. When I returned and was ready to drive the suburban back home it just "clicked" and I knew what that sound ment so I hooked up the trickle charger for about 30 minutes and it started and charged at 14 volts approx like normal. I looked down at the outside temp on dash and it said 55 degrees. Hot air was coming out of all vents even though it was on "auto" for 60 degrees. I pulled the BCM fuse and left it out for about 5 minutes and replaced it and found 55 degrees on outside temp again (even though it was 98 degrees outside) I had cold air on driver side but scalding hot air on passenger side!
I had to drive the 120 miles back home with just cold air on driver side and vents closed on passenger side and widow barely cracked open so I would not have a heat stroke.
I figured it would somehow reset itself after two days but no way, still same hot air on passenger side. I try'd all settings I could and now have cold air in rear passenger seats and back but NOT passenger side front.
I have discovered this condition only happens when the battery is down too low to start the engine, it is scary sometimes to see the volt meter flucuate between 12.8 and 14.6 volts and was told the ECM controls the charge voltage only when needed.
Does the BCM need a new program update or something?
I know I am not the only person who has had this problem and looking for a little help before resorting to the good ol dealership.
Thank for listening.
J W
Last edited: