I read most of this post, but not all, since a lot of expensive parts have been replaced, maybe not the one with the problem. On the 93 truck (vs my 94 I'm now very intimate with the A/C on) it use a 3 position pressure switch (low/med/hi) vs the 94> (low and hi).
Reading thru these posts, you seem to have a consistent problem with pressures. IMO/E you have done way more than you should have for the problem (1 expansion valve was a PITA for me, I can't imagine 3). If you aren't getting the proper pressures, that means the pressure switch is most likely toast. That pressure switch is the primary factor in proper clutch cycling, and I suspect only 1 of the stages in that switch is operating properly. Wtih all the work on the A/C, you never really had consistent pressures. That's usually caused by a malfunction in the pressure circuit.
Not sure you want to spend more money, but that's sure where I'd be going (and am later today with my 94 = bad switch, improper A/C compressor shutdown - too much focus on expansion valve and dryer)
I know the 2 position part number is 70USD or so, I don't know the price on the 3 position
HTH
Scott Justusson
Reading thru these posts, you seem to have a consistent problem with pressures. IMO/E you have done way more than you should have for the problem (1 expansion valve was a PITA for me, I can't imagine 3). If you aren't getting the proper pressures, that means the pressure switch is most likely toast. That pressure switch is the primary factor in proper clutch cycling, and I suspect only 1 of the stages in that switch is operating properly. Wtih all the work on the A/C, you never really had consistent pressures. That's usually caused by a malfunction in the pressure circuit.
Not sure you want to spend more money, but that's sure where I'd be going (and am later today with my 94 = bad switch, improper A/C compressor shutdown - too much focus on expansion valve and dryer)
I know the 2 position part number is 70USD or so, I don't know the price on the 3 position
HTH
Scott Justusson
