98 silverado ac / heat controls not working
 

Hi,

I just picked up a 1998 z71 chevy silverado to use as a winter / work truck. Pretty sweet all around, with one exception. The A/C & heat don't seem to work. More precisely the controls don't seem to work - I can turn the fan on and adjust all the speeds just fine, but changing the temperature and changing which vents to use does absolutely nothing. One of the previous owners did a pretty hack job install of a new head unit right above the controls, so that is my first thought - anyone have any ideas or suggestions?

-Thanks

My 98 has similar issues. The temperature control works, but the vent selector is a bit..uhh... personalized. No matter which setting it is on, 90% of the air will come out of the defroster. I can crank it all the way and have it set to come out of the face vents and I can hear the fan working hard, but all it will do is kind of piss out of the vents and will blast out of the defroster. Same thing with all the other settings.

You can see why I'm curious to see how people answer this one

I would check the motor that switches the vents under the dash. They are known to go bad (the little gear cracks or strips). With the motor off you can manually change the vents to free them up in case they are stuck. The one that changes the vents is towrds the middle on the drivers side. It is a little motor that bolts to the side of the A/C plenum down there. I would bet that would fix both of you up.

Yeah I checked that motor and door out on my truck and unless I'm doing something wrong, evrything checks out. I mean the motor is fine and works when it should and the door moves and seals correctly, but it seems to me that all the door does is decide whether or not it comes out by my feet or my face. I could be completely wrong on this but I think whats broken on mine is something else

You should be able to get it to blow out the vents from there as well. Remove the motor, turn your blower on, and move it slowly by hand. It should go from feet to face to defrost. There is also an arm down there that can come off and will cause that. I couldn't figure out what was wrong with my last one until I looked at my buddy's truck (that was working properly) and then it was very obvious.

In case anyone was wondering... I ended up taking it to the dealer for this one... they said the control panel itself was fried and just replaced that... and magically I have heat again!