Replacing AC Compressor NO POWER to it! HELP PLEASE!

Hi there. My mechanic (he's done quite a few things for me and I trust him) just called about my new compressor (not rebuilt) he installed in my '95 Eldo, but it won't power up! He claims to have FSM access via the web. I just hope one of you fine people might be able to steer us in the right direction. Thanks in advance.

low pressure or high pressure cutout switch? that would be my first guess.

low pressure or high pressure cutout switch? that would be my first guess.
THANKS! I'll relay that.

if it was low on freon before it may have set a low refrigerant code that may be needed to clear out, other than that, yes, the pressure switches, or even the relay, fuses. there should be a few different fuses in the system.

Mechanic has given up. Off to dealer ($$$) 7:30 am Pacific for PROBABLE (?) Powertrain Control Module. Now I have installed NEW (not rebuilt) Compressor, Accumulator, Rec/Dryer and exp tube, etc etc. ANY THOUGHTS??????? I hope this does it!

Mechanic has given up. Off to dealer ($$$) 7:30 am Pacific for PROBABLE (?) Powertrain Control Module. Now I have installed NEW (not rebuilt) Compressor, Accumulator, Rec/Dryer and exp tube, etc etc. ANY THOUGHTS??????? I hope this does it!disconnect the battary ground cable for 30 second and try it again

disconnect the battary ground cable for 30 second and try it again
SO..........I'm on my own now, solo, before I take it in--- IF I do this, what next? Start the car and turn on the AC?? Do I risk hurting anything?

SO..........I'm on my own now, solo, before I take it in--- IF I do this, what next? Start the car and turn on the AC?? Do I risk hurting anything?


I'm getting "bounced" all over on this one--A.C. compressor (new GM) won't power up. My non-dealer mechanic installed it, along with accumulator, rec/dryer, exp tube etc etc. Thought it might be relay, but no. Local expert says PCM (hasn't seen car). Mechanic has given up. I had an appointment at ($$)dealership-now cancelled 'til Tuesday morning. IN FORUMS I've been told so far .... low pressure or high pressure cut out switch may need replacing. AND/OR disconnect battery for 30 seconds because the flag will still say do not power comp unless this is done (I think it's safe to ASSUME he tried this, but I can't find out for 2-3 hours). IF, that's IF- he did this already and still no power, what do you think? IF he didn't, is he a BOZO?? THANKS!!

The ECM will shut down the A/C compressor when the Freon level gets low. Like when you change the compressor. Disconnecting the battery will reset this code. No harm done. Another way is to, with the ignition ON (but not running), press (on the HVAC controls) OFF and WARM at the same time for 5 seconds or so. This will bring up diagnostics. Follow the FSM to find trouble codes and reset the A/C compressor turn-off.