First post, let me try to be a specific as possible.

I have a 2001 FWD blazer 80K miles. Basically I don't have any heat coming out of the vents, just cold air regardless of the setting on the temperature control (manual).

In addition to this problem,the air vent directional control does not function. Regardless of the position, it blows the air through the dash vents. The A/C works, but this past summer I had a short period of time when the compressor just stopped for no reason and after about 5 minutes it restarted. That seems to have resolved itsself (false hope, I know).

The BCM was replacedabout two years ago. The cooling system has been serviced and the hose temperature in and out is the same.

I have disassembled the dash and see the various vacuum pots and hoses. I removed the switch panel for the heat and all the wires seem to be snug. Shaking various wiresdoes not change the result. I have checked the fuses at the end of the dashand they all look ok although I haven't replaced them. The one fuse under the hood for HVACin the box also appears OK. I can also report that the body control module shares circuits with other componets such as the crusie and the instrument panel. Everything else seem to be working OK. Given that two of the three controls on the switch panel are not working I would suspect electrical but just a guess on my part.

Any help would be appreciated. Chevy will charge me $49.00 just to tell me whats wrong.

 

Had the same exact problem in my '04 Stratus. Thankfully it was still under warranty. Turned out that the cluster of controls for the AC/Heat was bad. The part was $300 and labor would've been $400+ if not for the warranty. It's an easy job..just simplely take out the old and plug in the new.

 

Thanks, turns out it was a loose vacuum line and I reflushed heater core and got some heat, not enough, but better. Also, on top of the thermostat housing there is a "plug" for lack of a better term. Looks like a 1/2 drive and about 3/4 inch thread into the housing. What is it and what's it for?

 

Could you possibly take a picture of the plug you are concerned about?

 

Sure, here you go, note red arrow pointing to it. Prespective is from front of truck, looking down.

[IMG]local://upfiles/9182/D889F6C878AA47CF97BC40659CC4001B.jpg[/IMG]

 

That's what I thought you were talking about. It just opens up into the lower part of the t-stat neck. It is possible it is used for a heater hose on some other vehicle which uses this motor.

 

I thought it might be useful for flushing or for letting the air out. Thanks.