No heat or air conditioning

You need to clarify a little . No heater , or do you mean there is no air coming from vents . This would be a heater blower motor problem . Or is there air coming from the vents but it's cold , no heat ?

The temperature blend door is stuck on the A/C side ! Do you hear a clicking noise behind the dash ? Has an electrical controlled actuator that switches a door inside heater - A/C box from A/C to Heat . So the blower is blowing air over the A/C evaporator core all the time , not switching !

the door actuator isnt working

I assume your heater setting is electric control, if so either your defrost and floor heat switch failed or wire problem. For the air not hot, check the heat control valve on the top of the hose it should be in front of the firewall. I don't know your car is using mechanic valve or electric control valve. Anyway check there first. Good luck.

It sounds like your blend door isn’t operating correctly . The blend door simply is a flap that is designed to close off heater core when it’s calling for A/C , and opposite for heat . Check to see if it’s operating

you might want to check to see if your blower motor went out. that would prevent any heat from your engine coming out your vents. and as far as the a/c is concerned. one would be to see if you still have freon in the system other wise if u hear a grinding noise coming from were the condenser is located than the clutch went out of the a/c.

1. Check the air conditioner fuse and replace as necessary.
2. Air conditioner system discharged. Have the system evacuated, charged and leak tested by an MVAC certified technician, utilizing approved recovery/recycling equipment. Repair as necessary.
3. Air conditioner low pressure switch defective. Replace switch.
4. Air conditioner fan resistor pack defective. Replace resistor pack.
5. Loose connection, broken wiring or defective air conditioner relay in air conditioning electrical circuit. Repair wiring or replace relay as necessary.

If theres no air from the vents then its mostlikely a bad blower motor resistor module, this is very common on these.

The compressor on the air conditioner in my 2000 GMC Yukon XL went out last summer. Had it and the whole line replaced at a local air conditioning shop last fall. Used it little before cold weather. Warm weather this spring and no cold air. We could hear the compressor trying to kick in. The shop told us that the control console was bad and had to be replaced. They told us the part was on back order and did not know if they would be abel to get one any time soon. We took the Yukon into the local GM dealership. They told us that the high side fitting was bad and that the freon was very low and that they would have to deal with that first to check the system. Called back to the air conditioning shop and they said they had a console come in and they would put it in and check the high side fitting. I now have cold air and questions. Bought Yukon in 2005 used, had always had problem of not switching to cold air once the heater has been used. We were told changing the console should fix that. It has not changed. I feel like the console angle was a scam, that the system was just low on freon. Each shop was blaming the other for trying to scam me. And what can fix the heat to cold issue? If anyone has answers I would sure appreciate the knowledge.

is the fan motor working at full speed
check for blocked cabin air filter
the vacuum only works the vent controls and as you can feel the changes of the vents , it is not vacuum