wesandmarlene

I have a 2003 trailblazer and am having problems with the air conditioning.
When I first start up the car if the air conditioning is cut off, as long as I turn
it to #5 it works fine, then if I start driving, it will keep on running. But if I
attempt to change the air to any other level while the vehicle is in motion it
cut off completely (no air at all). The only way I can get the air back on is by
turning off the vehicle, taking the key out, starting the vehicle up and putting
the air condition back on level #5.

The only visible problem to me (besides the air condition problem) is the three
lights that are on the console that are lit up which are the:

(1)
"Parking break" lite even though I have the parking break completly down
(2)
4 Wheel drive lite, even though I'm not using the 4 wheel drive
(3)
1 other lite, can't remember what that is right now, away from the vehicle...

Any thoughts out there are appreciated,

NCHEVYHEVN

Hmm at first when you said it only worked on high I immediatly thought well you got a bad resitor pack in the blower circuitry but I almost positive the blower motor is controlled differently.

Since you said other lights were on in the dash that would lead me to beleive that you may have a bad BCM(body control module). It's hard to say without a wiring schematic in front of me or looking at the car.

If wiring/electrical problems scare you as much as me then I think you best bet is going to be to have a GM dealership look at it. I would stay away from small run of the mill shops and stick with a GM dealership since it sounds like a pretty indepth electrical problem.

It probly wouldn't be too hard for a GM tech to figure out cause he could use the tech. 2 to see if he could communicate with the BCM and command the a/c to operate at different speeds and etc.