'03 Yukon Rear A/c Headscratcher...

[spikeacman]

First, thanks so much!! Appreciate your time!

 

Front A/C works fine...

 

REAR A/C ISSUES: What works, what doesn't, and what I've tried...

 

The controls for fan speed and ceiling/floor airflow work as designed...

 

It just won't heat or cool - "luke" only...

 

Raising or lower the rear temp setpoint to min/max levels has no effect...

 

Condensate dripping like crazy from rear A/C drain, but no cooling from rear vents...

 

I checked the actuators - the one towards the rear that controls the hot deck, it's not working...

 

If I move this damper manually to one stop, I can get hot air from either floor or ceiling vents, BUT...

 

If I move it to the stop the other way, I just get Luke air, not cold air I'm expecting ...

 

Running about 180/40 @ 1500rpm, front a/c suction line is nice and cold - sweating to the y-block...

 

But the rear a/c line is 65-70 degrees where it exits the rear cabin underneath in the back...

 

At first, I was thinking clogged orifice or bad TXV (which one does it have?)...

 

But since I can't get HOT air either out ot the rear a/c with the temp raised to the max, I wanted to see if I'm missing something before I start getting into the sealed system...

 

Right now, I'm leaning towards hot air from the rear heater core is getting recirculated back into the rear evaporator somehow...

 

With the one damper not working as it should, I'm thinking maybe there's another one stuck mid-position or something...

 

I'll owe someone a cold one for help on this one - Thanks again in advance!

 

Rob