This is the newer body style with the 5.3 engine. I know the problem is either the control in the dash, or some stupid little electric operated door under the dash that is not letting the heat come through for the defrost/floor heat,etc. The rear heat works fine, but we REALLY need a defroster:Smarty: Has anyone else had the same problem that can point me in the right direction to what the fix is, and parts cost? Don't forget to tell me if the whole damn dash has to come out to get to the guilty culprit. Thanks in advance. Tom
Is it blowing cold air or not blowing at all? I have an 01 Silverado and had no heat last year, just cold air blowing from the vents. I had the heater core flushed out and all was well. My system had never been opened and there was alot of junk built up in there. If you have cold air blowing, might be worthwhile to try a flush. If you have nothing blowing out the vent, I got nothing.
If it has actuators like my Riviera, that is probably the problem. All the actuators on my Riv are accessable from below without taking the dash apart. Either the small electric motors go, or the gears crack or jam up. Have a look.
Thanks for the reply Tom. Not the heater core, the hoses are both hot going into and coming back out of the heater core, plus the rear heat works fine off the same heater core. Nothing but cold air blows from the vents. Doesn't matter if it's on defrost,floor heat,or dash vents. I was hoping someone may have had the same problem, and could tell me exactly which actuator under the dash is the problem. From what I understand, there are either 6 or 8 actuator'sou:
Looked at a repair manual at the auto parts store, and it had nothing as far as a picture(diagram)of the heater box,and the location of the actuator's,and a description of which one is which. This GMC is the biggest turd I've ever owned. The 5.3 engine is a fantastic piece, it's just too bad GM built a rinky-dink problem plagued turd around it. 5 passenger side power window motor/assembly's Half the Speakers don't work Alway's has blown fuses Gas gauge quit reading right 3 years ago(at @ 70k miles) Some day's it just won't run right until you shut it off,and restart it It just turned 100k miles last week.
i have a 2001 tahoe and love it. the heater resistor in the heater box goes. my did. its like $35 for the part at the dealer and not that bad to put it in.
