The A/C on my Ex didn't work when I bought it...neither did the heat but that's fixed now. Now that warm weather is approaching, I'm working on the A/C as my wife has boycotted any further road trips until it's fixed. I took it to a local garage where they pulled a vacuum, charged it with freon, and added a couple of cans of dye. The intention is that I'll drive it for a few days or until the A/C stops working and they'll then look for the leak with a black light. I now have frosty air up front but only ambient temp air in the back. The rear heat works well and it switches quickly from heat to no heat with no odd noises so I think the blend door actuator is working correctly. Yesterday, I noticed that there was no temperature difference in the A/C lines going to the rear. One should be hot and the other cold. The first thing that comes to mind is a clogged expansion valve in the rear. I wanted to get your opinions prior to tearing into it though.

 

 

Expansion valve is cheap, however the whole system has to be evacuated to replace it/troubleshoot it. That part isn't cheap...

 

Right? Just shucked out $165 to have it charged and dyed so I could find the leak. I'm working on the assumption that, since it was completely empty, there must be one somewhere. I'm kind of hoping to find the leak and fix it and the expansion valve at the same time.

 

If I recall there is also a strainer in the TXV as well, past history has also shown on older systems that sometimes the desiccant bag will break sending desiccant through the system, desiccant contamination is probably not an issue for you as your front evaporator would suffer performance too. You might have a bad compressor shaft seal.

 

That makes sense...the desiccant would contaminate the whole system. I was thinking compressor seal too...kind of hoping compressor seal actually. Although it isn't the cheapest part of the system, I'd rather buy and install a compressor than have to dig one of those evaporators out of the dash/rear. I'm waiting on it to stop working now so we can look for the dye.

 

The TVX valve probably is bad, hence no rear air. I would also replace the orfice tube. It will be clogged partially I am sure.

Leak wise if you can't see one visually otherwise, pull off the grill and inspect the condenser. I have had those leak when objects strike them.

On our X's IIRC there is no desiccant/receiver dryer. There is however an accumulator. As to the TVX valve, when I replaced mine, no screen to clog in it.

 

I know we don't have a separate receiver/drier component, I'm thinking there is one inside the accumulator since the PAG oil is so Hygroscopic.
Every descriptor in the shop manual describes it as a Suction Accumulator Dier. I broke the refrigeration cardinal rule and didn't replace mine once the system was opened, I only had it opened for a short time to replace the condenser, then pulled a long deep vacuum.
Just thinking out loud is all...