rjoenga

My 2004 Suburban is having a problem with air conditioning. The compressor is running, Freon is O.K., but no cool air coming out of the ports. Someone mentioned a possible damper problem probably caused by a faulty operator (servo?). Suggested I may have to remove the complete dashboard to service it. Does anyone have any comments on this?

Thanks,

rjoenga

73shark

Might be the blend door. Not sure how much has to be removed to get to it.

MDTAHOE

Pinch the heater hoses closed and see if it gets cold. What are the hand low side pressures?

rjoenga

Thanks for the reply. I'm quite sure the problem is with the Blend Control Module. I've been doing a bit of research on this Chevy Forum web site and I see that I'm not the only one with this problem. So far, I've tried a couple of things. First, I tried disconnecting the battery to see if I can reset the BCM, but now I have extremely hot air coming out on the driver's side and cooler (but still warm) air coming out of the passenger side. Second, I set the rear controls on manual - maximum cooling and the front controls on manual, maximum cooling and minimum fan speed. The rear seems to be blowing cold air, but not quite enough to cool the whole car when it's 88 degrees outside. The front still has hot air coming out, but much less at the minimum fan speed.

I recently ordered a CD with a complete service manual on it and it should arrive in a couple of days. Hopefully, it will give me some idea as to what needs to be done to replace the BCM.

Thanks again for your reply!

rjoenga

rjoenga

Hey MDTAHOE,

As far as I can tell, there's only one port in my suburban available to measure low side pressure, and it is located directly after the orifice plate. The pressure at this point is holding around 45 psi, which I believe should be good. I like the idea of pinching off the heater hoses to see what happens, but should I be concerned about the resultant pressure inside the hoses if I do this? And if not, how long can the hoses be pinched off without causing a problem? In any case, I'll try this tomorrow morning.

Thanks for the suggestion.

rjoenga

73shark

45 psi seems a little high but if it's 134a then maybe not. Not too familiar w/ its pressures. Pinching off the hoses won't create any more pressure than is already there.

MDTAHOE

You could pinch them off for ever and not have a problem.