Need a/c gurus for 83sc
 

hello there, wondering if someone can help me diagnose an electrical problem with my 83sc 911 a/c compressor not firing up...I recently did almost an entire redo of the air condition replacing the hoses and evap and front condensor. I then vacuumed the system and replaced the oil and when i was ready to put the freon the compressor wouldnt turn on. The wire has no juice nor does the front condensor blower turn on but he evaportor motor does blow ...I just replaced the evaportor blower relay in the box thinkn it may be alittle burned and the new relay did not change anything.....I need help ....damian

You may have a pressure switch that disables the compressor if the system pressure is too low. You can add some refrigerant with the compressor off to get above the pressure required to activate the safety switch. When adding with the car turned off, open both hi and low valves on the guage set until the pressure is at least 30psi or so. MAKE SURE to close the high side valve prior to turning on the compressor. If this doesn't solve the problem it may be a fuse or bad relay.

If you have the original York compresser (big rectangular unit), there is not a high or low pressure switch.

They will even run with no freon in the system.

Guessing it's an electrical problem.

thanks for the replies, My compressor is the new sanden 507 and i dont have a pressure switch....i changed the relay inside the smugglers box thinkn it may be half blown since my blower in the cabin still works when i turn the switch on for the a/c on the lower console...im stumped....My 25amp fuse in the fuse box for a/c is good and so are all the others in the fuse box....any other places to look??? The compressor would work before i took it all apart but just needed upgrading and took it apart...Oh and i thought it being low on freon was the reason for the clutch not engauging so i added a can, then i thought it may not be enough so i added another, all went in i guess due to gravity without the clutch working....damian

don't waste your time with the a/c on that era 911 -they didn't cool well when they were brand new!

A/C in my SC is great.

Really.

Damian,

After buying the front condenser and evaporator from Griffiths I had a similar problem. Griff finally had me loop the green and green/white wires at the temp switch together. That takes the switch and or the capillary tube out of the system.

It's worth a try... You can't hurt anything!

"..You can't hurt anything!..."

Oh, but yes, you can..

Run the compressor "open loop" that way for too long and it will start ingesting liquid refrigerant....NOT GOOD.

Don't know if the system on an 83 is similar to the one on my 87, but when my compressor wouldn't engage I tracked it down to a bad temperature switch.

There is a relay in the smugglers box that is likely the problem

Mitch, i did the connecting the green and green/whi wire together and BAMM that was it!!!!!!! Ive got a bad temperature switch, or better yet, too much messing with the capillary tube during installation and it developed a crack, and it screwed it up. So now i can get to where i was at and putting some freon in the system .....THanks to everyone who helped on the my problem, Mitch/Ken. This forum is such a invaluable tool, and the people who participate....Damian