This respondant is an idiot.
1993 most GM cars and trucks were R12
Nissan was R134a in 1993
GM was in 1994
: >94 Jimmy 4x4, 4.3L W engine. My A/C is still R-12,
: Impossible. All vehicles sold in the US since 1993 use R134a. Either
: your truck is older, or you are mistaken as to the refrigerant.
: >neither of the 2
: >shops I trust has any left to re-charge the system, but one still has
: >the equipment to recover and re-use the R-12.
: A shop that does not possess recovery equippment is not qualified to
: do A/C repairs. Also, it cannot legally attempt refrigeration system
: repairs. It can do electrical A/C work.
: >The A/C worked last
: >week after having it to one of the shops and they jumped the
: >compressor to test it for operation, it worked but they didn't want to
: >go farther.
: This means that they are smart enough to stay away from work that they
: are not qualified to do.
: > The A/C worked when I went to pick the truck up, so I was
: >2 days later, it stops working again, jiggle the connection on the
: >pressure switch in the accumulator and the compressor kicks on, GREAT!
: >Not working, AGAIN. I jumped the 2 contacts on the lead for that
: >pressure switch and the compressor came on, the accumulator got nice
: >and cold and the air coming out of the vents was cold. Would this
: >mean the pressure switch is bad
: That is one possibility. There are others.
: >and I can take this to the shop with
: >the recovery equipment to have them replace the switch?
: You can do whatever you wish. I'd suggest that you find a shop that
: knows how to do A/C work. For what it's worth, the low-pressure
: switch should be mounted on a Schrader valve, and would not require
: discharging the system for replacement. A competent A/C shop would
: know this.
: >BTW, I'm not spending $250 to have the most-trusted shop disassemble
: >my A/C system and do a proper conversion...
: Cold air costs money. How comfortable can you afford to be?