A/C wireing problems

[S Webster]

Hy folks. Say, I've been workin' on my 93 SST. Weather's getting warm, so I decided to service my A/C. The clutch wouldn't engage from dash controls, so I jumped power to it and it worked fine. So, slightly cool air, sight glass showed lots of moisture, so I evaced. it flushed it, pulled 23" of vacume on it for about an hour,and switched to 134. Still jumping it, the thing makes 40* @ ctr. dash vent. Nice. But, I've still not been able to get dash controls to work. Checked all fuses, replaced both relays, no help. I pulled the glove box to look at the cut relay, and t-stat, but you can't see much. Don't know where to go next. I'm powerin' it thru a rocker switch on the dash, but I don't like bypassin' all the saftey devices, and temp controls. Ideas? Thanks, Steve.

[Legacy777]

I'd suggest looking at the pressure switch on the receiver drier. That's really the main component that will keep the system from operating properly. You can try jumpering the proper leads for the trianary switch to see if the dash button works. If it does, then you know the issue is the pressure switch. If that is the case, you'll have to depressurize the system to replace it, but should be a pretty easy fix.

I don't have access to a wiring diagram right now to indicate which pin does what, but that's probably where I'd start.