Hey, new to the site and have a 2002 Tahoe LT with 206k miles and the "Electronic Climate Control System" (picture attached).

The temp blowing through the vents is always hot, and seems hotter than it would be even if you had it to the max temperature setting (82F). It blows hot when it is set to the coolest temperature 66F, or on any other temperature setting for that matter. Also when the fan is in the off position, I still seem to get more air flow than usual, I know you naturally get air as the car moves but it almost comes through like the fan still seems to be running a bit. But when changing the selection of the fan speed/strength it seems to operate fine with just some minor squeaks and noises as a well used 2002 truck would make in 2020, never the less, the fan variation seems to work okay. When the AC mode is selected it continues to blow hot. The zone selection also does not work, regardless of whether I move the fan zone from the floors, to the defroster, or wherever, the fans only blow from the main ones that go across the front of the vehicle at driver level (next to wheel, radio, glovebox, etc).

I am not a mechanic but I am trying to save money and fix this before I go to one. I am now familiar with the location of the fuses on this truck and also have seen online that the controls are known to go bad (the one in the pic). Has anyone dealt with this problem and know a simple solution for a DIYER? I am going to check the fuses tomorrow as it is now dark. But I would guess the control has just gone bad seeing that it still has power and its lighting but doesn't function. Also note that before this happened, I had decent AC and even without AC you could have mild to cool temps blown out of the fan. From what I have seen the control temp is an easy change and you can find them for about 130$. Any input on the problem, parts, etc.
would help.

Thanks,
Connor

 

I don't even know why Chevrolet used the "66 to 82" F temp range on the dash, to be honest since it's unlikely that it operated exactly at those temps like that when brand new. It sounds to me like you have a bad control unit at the dash, that is using a default mode setting of sorts, which is why the temperature is higher then normal. That said, I would absolutely go through all the fuses, both inside your vehicle and the fuse and relay box mounted under the hood on the driver's side fender. As a person trained in automotive A/C systems, I'd check the A/C compressor, but I do not believe the A/C system is the issue here at all, since the climate control unit cannot even switch to floor outlet mode, not simply blow the hotter-then-normal air from the upper dash vents, as you describe.

To the best of my knowledge, in the past, General Motors, and Chevrolet, did/do use a system to keep unwanted environmental air pollution and possibly carbon monoxide from collecting in the passenger compartments of their vehicles, which was and still is a good idea, in part by not allowing the climate control fan to stop completely, thereby possibly keeping the driver's from succumbing to falling asleep due to carbon monoxide inhalation, and you will notice the vents in the doors of almost all GM vehicles, to keep the air flowing through the interior. But I believe they stopped producing vehicles with the "constantly-on" C/C fan back in the late 1980's or early1990's.

Both my 2015 Chevrolet Malibu and my 1998 Chevrolet Silverado K-1500 pickup have the door vents, but the climate control fan does come to a total shut-off when set to do so. However, the natural movement of the vehicle will keep the cabin/passenger/driver compartment with a decent amount of clean outside air, perhaps even when it is set to recycle mode, which I never use at all. GM made a wise move with the adoption of that system, in my opinion, and it's one more reason that I like General Motors vehicles, particularly all of the Chevrolet's that I have owned.

 

Thanks Oilcanhenry!

I think it is the control system as well. As said I am not a mechanic and wanted a second opinion before I bought any parts/made changes. Thank you for the information on the vents and air flow as well.

Much appreciated.

-Connor

 

Learn how to visually check/confirm that the center of the AC compressor is spinning (not just the outer pulley) when the AC is switched on.

If so, then maybe like the issue I had on our 2005 Yukon: an actuator under the dash would flip and cause hot air from the heater core to come out the vents, not good in Arizona !

Hardest part was removing the underdash cover for me, had to grind down 5.5mm socket shorter at both ends to fit. For first year I used a screwdriver to flip the acuator to the AC position then disconnected the electrical harness. Later I bought an aftermarket Dorman actuator and fixed it correctly.