Rear AC Control and not blowing cold

[Jazz]

Hey all-

I'm waiting for the pitman arm, idler arm and bracket to show up tomorrow, so I thought I would take a stab at the AC.

I recently replaced the AC Compressor, the dryer, and the orifice tube. (Actually, added the orifice tube- when I went to replace, there wasn't one). Thanks Meinike!

Took it to a shop- they charged it up and it's blowing cold. In Arizona, that's pretty valuable. Especially in June. And with a 18 month old in the backseat.

So, when I went to pickup the truck, I checked the rear ac and put it on max. It started to blow and went to max. I didn't think anything of it. 30 minutes later, it still wasn't cold, but the front was ice cold.

I took it home to play. I tried to shut off the blower in the back, and I can't. It doesn't matter what position I use, it's still at full blast in the back. I found a few parts on ebay, (its disco'd) but I figured I'd try to clean it. Is that sucker glued?! I can't seem to find a pry spot. I attached a photo. How do I get that switch off?

The rear ac temperature issue. From what I can tell it's going to be a blending issue or a thermo expansion valve. I can't do much with either, because the system is charged. I think this is one of those things where the shop is going to have to evac the system and take care of it.

Any ideas?

Thanks!

 

[east302]

You should have a thermal expansion valve which sends refrigerant to the rear core. There should be a junction near the radiator, believe it is y-shaped but am not sure. It probably has a screen on it, this may be clogged or the valve damaged if refrigerant isn't getting to the back evaporator core. It could be an issue or blockage in the rear core? I don't know if it could be flushed, but would be inclined to take it back to the shop since any repair there would involve replacing refrigerant.

As for the rear blower, here are the diagnostics from a 1998 for the rear blower operating continuously. I'm not sure how you get the switch out of the headliner, but it seems like it should just pop out.














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[Jazz]

That is fantastic! Thanks!

I need to pick up a test light. When they say cavity they're talking about pins in the connector?

 

[east302]

Yep. Or use a multimeter and see if you get voltage.


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[Jazz]

Looks like I might have a bad resistor! Unfortunately it's been quite awhile since they were made. Anyone know where I can find one? Part gmc 15 80835