I have a 2000 LeSabre Limited with dual automatic climate control. Until recently it would blow only cold air with a heat- requiring temp. selected. (72 deg @ 44deg xtal temp) I solved the heat problem by backflushing the heater core. (No valve, but LOTS of sediment came out.) However the A/C compressor continues to run, either all or most of the time, with similar temp. setting and reading to the above. All other CC functions (blend doors, outlets, temp. accuracy) seem normal. What could be causing the compressor to run in spite of the obvious "heat" control settings? Is that really part of the automatic CC unit functioning?

underdash near glove compartment a solenoid pack with plastic tube different color you can find your problem

You likely have a faulty blend door. It could be electrically, mechanically related, or even a broken door. It may be the blend door motor, or possibly the temp sensor.

Could be a vacuum actuator problem. or just a vacuum leak, period. I have a Jeep that when it has a vac leak, the climate system defaults to the defrost, no matter what you set it at.

You will have to check the flap operating controls behind the centre consol as anything could be wrong from a vacumn pipe to a operating mechanism ,even the computer controlling the climatic control .

I have a 2000 pontiac grand prix with a digital climate control system. The heat quit working, it doesn't blow out any heat. Now that it is warm outside the air stopped blowing out any air. The digital temperature on the climate control is not correct. When it states that it is below 30 degrees on the ext and it is warm outside the air wont be cold. Once it starts going above 30 degrees the air gets colder. Today the blower stop working all together. Was told it maybe the climate control unit was bad. You can hear the door opening/shutting when you switch the temp from cold to hot. But there was no heat blowing out whatsoever in the winter time. Could you please give me your opinion on whether or not it is the climate control unit or something else?

My 02 Century has dual temp controls . One for driver for passenger. Make sure you don't have the dual climate enabled and just set for heat on your side and AC on the passengers

I would bet that your vehicle has what they call dual climate control. This feature allows for a great variance in tempature from driver to passenger side of the vehicle. Take a look at your owners manual as to how to turn it off. I believe there will be a button on your climate control that says "Dual" hit that button and retry it should answer your problem

the climate control thermostat is not opening the valve to let the warm coolant in

fault temp sensors
still can be a worn or stuck shaft flap at the actuators
or actuators is still faulty

Temp. actuator stuck on heat , probably . Manual or automatic climate control . Electrically controlled temp actuator , or the door is stuck in heat side.