Rear A/C problem

[rolfsent]

When I bought my 1999 Denali I had no air conditioning at all front or rear. I replaced the high pressure switch and that fixed my front A/C problems. It's now getting hot enough that I'm getting complaints from passengers in the back that it's not cold enough. The rear vents blow just fine, but it's only hot air. How do I get this rear A/C working?

 

[SunlitComet]

perhaps a broken or plugged thermo expansion valve on the rear evaporator.

 

[rolfsent]

perhaps a broken or plugged thermo expansion valve on the rear evaporator.

Where is the expansion valve? And how do I get the rear panel off to access the rear air components?

 

[SunlitComet]

Rear

Auxiliary Heater Module



Remove or Disconnect

1. Negative battery cable.
2. Recover refrigerant.
3. Rear quarter interior trim, as necessary.
4. Right rear quarter trim panel.
5. Right rear wheelhouse.
6. Rear heater hoses from auxiliary heater core (32), if equipped.
7. Auxiliary refrigerant hoses (20 and 21) from auxiliary evaporator (26).
8. Electrical connectors, as necessary.

Removing Case Clips

1. Heater/evaporator case cover.

• 1. Remove case clip.
  2. Remove eleven case screws.
  3. Separate case halves.

1. Pipe insulator
2. Evaporator core (26).

Install or Connect

1. Evaporator core (26).
2. Pipe insulator.
3. Heater/evaporator case cover and screws. Case clip.
4. Auxiliary heater case to the vehicle.
5. Auxiliary refrigerant hoses (20 and 21) to auxiliary evaporator (26).
6. Rear heater hoses to auxiliary heater core (32), if equipped.
7. Electrical connectors, as necessary.
8. Right rear wheelhouse.
9. Right rear quarter trim panel.
10. Rear-quarter interior trim, as necessary.
11. Negative battery cable.
12. Charge system.
13. Check system for leaks.