wildncrazyguy
Newbie
- Joined
- Oct 14, 2014
- Messages
- 33
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I picked up a new to me 1998 Suburban back in December 2014. One issue I'm trying to solve is HVAC related. Try as I might, I've not seen my issue discussed anywhere so I thought I would see if anyone here may have an idea to throw at me.
All, as far as I can tell, including rear controls seem to work properly. Air blows where it is supposed to, fan speed correct, heat/cold fine, control unit lights function when pressed on or off. Everything seems ok, except the one issue I have is when the recirculation button is pressed or the AC button is pressed and in the MAX/vent position, the system immediately moves the mode door and prevents vent position and starts blowing the air out the floor vents and maybe some in the defrost windshield area, not 100% sure on that. It closes the vents off, which is of course where you would like to have the AC blowing at you and not on your feet.
Now AC seems to work and cold air blows in your face, just not on MAX AC which automatically lights up the recirc button. Seems to me the recirc button is the root of my issue here and am wondering what direction to take.
With all that said, I do have also a 1998 K1500 pickup with a control unit almost identical to the Suburban, just without the rear window defrost as my truck does not have that feature. It is a real pain to take my dash bezel on the truck off, but can be done. I thought about swapping the control units to see if they acted the same in both vehicles, like the Suburban now works and the truck is now broke. Advice as to whether this route might definitely indicate a bad control unit in the Suburban, worth the risk of breaking? I just don't really want to take the risk of breaking my truck unit which works perfectly fine and/or the Suburban which I think could be bad, but may be perfectly fine as well.
It may not be my issue even at all and I'm hoping someone here may point me to a resistor or relay or something... Someone with experience in this era HVAC. I did look at the mode door on my truck and Suburban and they seemingly move exactly the same, except the Suburban wants to move when the recirc button is pressed and the truck stays in place as far as I can tell. I will do more research on that as soon as possible to confirm this. In any case, thanks for any help or insight.
All, as far as I can tell, including rear controls seem to work properly. Air blows where it is supposed to, fan speed correct, heat/cold fine, control unit lights function when pressed on or off. Everything seems ok, except the one issue I have is when the recirculation button is pressed or the AC button is pressed and in the MAX/vent position, the system immediately moves the mode door and prevents vent position and starts blowing the air out the floor vents and maybe some in the defrost windshield area, not 100% sure on that. It closes the vents off, which is of course where you would like to have the AC blowing at you and not on your feet.
Now AC seems to work and cold air blows in your face, just not on MAX AC which automatically lights up the recirc button. Seems to me the recirc button is the root of my issue here and am wondering what direction to take.
With all that said, I do have also a 1998 K1500 pickup with a control unit almost identical to the Suburban, just without the rear window defrost as my truck does not have that feature. It is a real pain to take my dash bezel on the truck off, but can be done. I thought about swapping the control units to see if they acted the same in both vehicles, like the Suburban now works and the truck is now broke. Advice as to whether this route might definitely indicate a bad control unit in the Suburban, worth the risk of breaking? I just don't really want to take the risk of breaking my truck unit which works perfectly fine and/or the Suburban which I think could be bad, but may be perfectly fine as well.
It may not be my issue even at all and I'm hoping someone here may point me to a resistor or relay or something... Someone with experience in this era HVAC. I did look at the mode door on my truck and Suburban and they seemingly move exactly the same, except the Suburban wants to move when the recirc button is pressed and the truck stays in place as far as I can tell. I will do more research on that as soon as possible to confirm this. In any case, thanks for any help or insight.