'94 S10 Blazer Ac Ducting System Not Working Properly

[Kharn]

A few days ago, my '94 Blazer (converted to R134A in '03, low pressure switch replaced in '05) would blow air so cold that it would almost freeze your hands on the wheel. Today, even on max it is just blowing "cool", not warm, but not nearly as cold as it used to be. Max A/C and full power on the fan produces cooling approximate to minimum fan & normal A/C previously, I can feel the air has a bit of a chill to it not from the speed of the air.

 

I checked the low pressure switch, sprayed its connection with electrical contact cleaner and wiggled it while connected to make sure the juice is flowing.

 

I hooked up the gauge from an R134A refill kit to the low pressure port, it showed pressure in the 45psi range.

 

The clutch stays engaged, it does not cycle on/off.

 

The metal cylinder with the low pressure port and switch is cold to the touch, with condensation present.

 

When switching from HTR to Vent there is a mechanical noise, like a small door opening. When switching between Off <> Max <> A/C <> Bi-level there are no noises similar to the HTR -> Vent noise. I remember previously hearing that noise when moving between Max AC and A/C, but it is not present now. Airflow changes locations properly between defrost, feet & vents.

 

Any idea where to look? How far into the dash am I going to have to dig to fix this?

[Kharn]

I opened up the access port in the glove compartment and removed the radio, the only piece I could see was the temperature control actuator, no luck finding the AC/Heat control door. Anyone have a service manual for this truck?