Rear A/C Not Working 2002 Tahoe

[tommyadrian5]

My Front A/C works great, but my rear A/C only blows air between outside temp and Hot Hot Hot. If i turn the rear a/c to full cold it is the outside air temp, if i turn it to full hot it gets very hot.

I referenced this thread below, which suggests replacing the actuator, but before I drop 90 on a new actuator I wanted to ask if a bad actuator would cause it to do what it is doing? Since it seems to work (heat is hot) could it not be that?

http://www.tahoeforum.com/showthread.php?t=9534&highlight=rear+air+conditioning

I notice that when i have the front and rear a/c 'on' the refrigerant line after the front rear split is cold for the front a/c and warm for the rear a/c at the splitter. Is this due to the bad actuator or do i have a problem in the refrigerant line? Any advice?

My second question is what the 'AIR' fuse in the under hood elec box controls. I inherited the car from my brother and the fuse for 'AIR' is missing. Anybody knows what this controls?

 

[tommyadrian5]

Nobody has any advice??? :-(

I pulled the panel off today and the actuator is working fine, moving between the two indicators for hot/cold. The blower works fine as well.

The compressor works fine and the front a/c gets cold.

It is like there is a clog in the refrigerant line, since it does not get cold like the front one does. Checked the pressure on the system, around 40 which is half ambient and should be correct (also matches pressure on my brothers tahoe which works correctly).

What would cause a lack of refrigerant flow to the rear a/c unit? Would a clogged evaporator hose cause it? I'm dumbfounded.

 

[tspain]

The rear expansion valve on the rear evaporater is stuck closed. You'll need to remove ther rear a/c case, and evaporater and replace the rear expansion valve. Be sure and evacuate the a/c system before opening a line.

 

[tommyadrian5]

The rear expansion valve on the rear evaporater is stuck closed. You'll need to remove ther rear a/c case, and evaporater and replace the rear expansion valve. Be sure and evacuate the a/c system before opening a line.

That makes sense. I checked the evaporator drain hose and it was fine. There was lots of mud on the connections inside the rear fender but i assume those are sealed.

How hard is the job you proposed. Should i dealer it or can a pretty competent home mechanic do it (assuming i can evacuate the system)...

 

[tspain]

Disconnect the heater lines (2,3) from the auxiliary HVAC module at the underside of the vehicle.

Disconnect the air conditioning lines (2,3) from the auxiliary HVAC module at the underside of the vehicle.

Remove the nuts (2) from the studs (1) that secure the auxiliary HVAC module to the underside of the vehicle.

Remove the safety stands.
Lower the vehicle.

Remove the right rear quarter trim panel.

Remove the electronic suspension control module (if equiped).

Disconnect the electrical connectors from the Auxiliary HVAC module.

Remove the fastener (5) for the upper auxiliary air duct (1). Carefully slide the duct up, into the headliner, until the bottom edge of the duct is above the air distributor duct.

Remove the fasteners (3) retaining the auxiliary HVAC module to the vehicle.
Remove the auxiliary HVAC module (4) from the vehicle.

 

[bigham]

Found this thread and I have the Same exact problem, Is $250 to change the part and $250 to flush sound right? Other than that wanted to say thanks for this post. It helped me.

 

[jimandkims]

Was this diagnosis and subsequent repair the cure for the problem - just got a 2004 Tahoe Z71 with the same exact issue! How much should I expect to spend to repair? Thanks.

 

[NCFD4303]

It is a common probelm if you have had a compressor failure.

:welcome:to the board

 

[jimandkims]

Not sure if it had a compression failure since I just got it but this seems totally logical. I actually am going to tap on the location of the valve - have had luck in the past of getting them to open. Thanks all.

 

[hendedo]

Did this solve your problem? Please let us know. good write up and directions for this repair. Thanks to all.

 

[Giggas45]

Rear Ac Blows Hot Only Actuators work fine. Broken flap!

So I have read about 50 post about the rear AC issues in the tahoe yukon family. Mine is a 2004 Yukon SLT. I pull the rear housing out and took it apart to find that the Temperature Actuator that controls the flow from the heating and cooling vents in the unit was broke. Now i know how to fix it but cant for the life of me find the part number or a parts list for my vehicle. Please help. I would suggest that you might have the same kind of problem.