Ok with the passlock problems behind me on to the next adventure. My 2000 blazer has poor to no heat. The BCM is out of a 2001 blazer with climate control where my 2000 just has standard a/c and heat controls. Could this be the problem? Or is it the heater core gone bad? Every once and a while I have to add coolant but it doesnt leak or smell.

 

BCMs have to be programmed for the vehicle. If your heater core isn't restricted, then that is likely your problem. The controls are considerably different between the manual & automatic A/C. A scan of the BCM would tell you whether it things there are problems.

 

Thats what I though. Can this BCM be reprogrammed to the correct heating system?

 

just a thought, Swartlkk mentioned 'if your heater core isn't restricted'
I would start there, pull the lines off the heater core and run fresh water through it both ways until the water comes out clear(and make sure it flows through easily)
It's free and will eliminate that possibility.

 

Yes, it can be reprogrammed to your VIN details. As we both pointed out, first check to make sure that you don't have a restricted or blocked core.

Then, if that checks out, I would get the BCM scanned for codes. That'll let you know if you need to get it programmed or not. If you get a bunch of codes stating that components are missing, then you know.

 

ok Ill start there. Thanks

 

Bad Radiator, and the heater core was restricted. Found a gm tech that will reconfig my bcm for a case of beer one day after work.

 

Ha cool. free beer is always a good plan B. I dont remember how many easy odd jobs ive done for a good case of it,or paid in beer for a job i needed done. Even had my mothers best spanish friend get us some Mexicans to help move to a new house for 2 bags of tortillas and 2 cases of budlight.

 

I just had an issue with the heat not working. All it would do is blow cold air. I started with a new thermostat. It was only $8, so I thought I would start there. Changed it out and bingo, we now have heat.

 

I had an issue yesterday with no heat. I did the thermostat, and this morning, still had nothing. So after checking the threads here, went out, and felt each of the lines at the firewall to see which one was hot...thinking a blockage. They both were hot. So, I went and turned on the heat again, and sure enough, hot air. Magic I guess.