Heater Control

I have a 2001 2500HD. My tempature guage seems to be "sticky". Once I turn it towards warm, it has a hard time adjust back when I move to cold and sticks on warm. I've been thinking about replacing the control unit with the automatic climate control version.

Does anyone know what the likely cause is to this problem? and will the automatic climate control unit hook up into the wiring harness I have now with my manual control unit?

Thanks in advance for any assistance you can provide.

My 2001 LS acts the same way. Can only get cool or cold air in the heat mode with the dial turned all the way to the left. Any other position might as well be full hot mode! Have you had any luck finding out how to fix?

I have the same problem with my 2000 base model. It's either hot or cold. No in-between.

I have a 01 2500 ls ad ive had almost the same prob if I leave the heater on for 30-40 min then it will become stuck in the heat mode the only way I have found to "fix" it is to turn the car off for atleast 30 seconds and open up the windows. I know thats not much help but thats what Ive been doing its only happened 2 times so I hope this helps.

I've got a 98 thats sticks also. Often my "Check Engine" light comes on & when tested at Autu Zone it shows I have a bad "Heater Relay Switch". Stll haven't replaced it & it is annoying sometimes.

I have a 01 2500 ls ad ive had almost the same prob if I leave the heater on for 30-40 min then it will become stuck in the heat mode the only way I have found to "fix" it is to turn the car off for atleast 30 seconds and open up the windows. I know thats not much help but thats what Ive been doing its only happened 2 times so I hope this helps.

I have the exact same problem. I can switch from heat to the AC and it does not switch over to AC stays in the heat mode. This is a real pain in Texas where it can be near freezing in the morning and in the 60s later in the day. If I pull over and turn off the car it will work when I turn the car back on.

Sounds like a common problem. After about 30 min. I have to set my dial right at the far left of the red stripe, almost in the blue to stay comfortable. Even if it's below freezing. 02 Z71 extended cab

2000 LS Silverado Same thing but when I want to go to cold after being on hot it takes about 3-5 days for it to switch over and I leave it in the cold position for this long and then it finally will magically go from all hot to all Freezing cold. And you guessed it when I want it to be hot again it only takes 3-5 short days for it to freaking realize that I want it blowing hot. And one other convienient feature REALLY HOT OR REALLY COLD No inbetween. Dealership put a new control unit and it did not fix the prob. Go figure.

There is a TSB out on this and other HVAC problems on or around 2000. There is a connector up over the right front of the dash panel. Pull out or down on glovebox, looking up at the RF corner near windshield, there is a small duct and wiring harness running along the windshield from left to right side. the harness connector they say is being pulled on because it is routed wrong. I pulled it off the metal clip and let it hang, pulled connector apart and picked out tight the female ends with a needle. Also check the 2 connectors on the back of the control head for loose connections. My 2000 has similar probs, my connector is alright. When I turn off AC button the compressor does not disengage. Also with the fan switch in the off position, when I take off, fresh air blows in through the vents. Have to hit the recirc button to shut it off.