The car is a '96 960 wagon with 209,000 miles on it.
A/C compressor clutch will not engage without manually applying 12v to clutch wire.
Last summer the clutch broke when doing a close to redline downshift while getting on the freeway. Now that summer is here again, I'm needing to fix the A/C for the wife.
So, I installed a new compressor assembly, orifice tube, expansion valve, receiver/dryer & o-rings, took the car in to have the system evacuated & recharged. They called back to say that all is good except the system will not engage the clutch. They manually put 12v to the clutch & system works OK. They spent an hour on it to say it's probably the control board in the dash. After searching the forums here, I've got the control board out, looked at it with a magnifying glass, haven't seen any solder joint issues. Tested the A/C on/off switch, OK. Relay under hood tests OK, fuses look good.
Anyone know of something else? Thanks for any input.

 

Sometimes those circuit boards are tricky to find the cracks. I'd replace the control unit, get one from a JY to be sure. The cost would be minimal... You have replaced everything else.

 

Well....I went over things that the mechanic shop supposedly did. The relay clicks when you turn on the A/C switch, 2 seconds later the idle raises up 100-150 rpm but still no clutch kicking in. When I remove the relay, I do not see 12 volts on the "30" terminal. I only see a "5" amp fuse labeled A/C in the same fuse/relay block on the left inner fender. I've checked the main fuse block by the battery in front right corner & also the fuse panel on the left side of dash.
Is there a fuse-able link somewhere?
Thanks for any ideas, Brad S.

 

I guess I did not see the 15 amp fuse labeled A/C compressor clutch (I only saw the 5 amp A/C compressor clutch relay fuse). It was blown. Kinda makes me want to go back to the mechanic shop that said I had a major short in the system. When I looked at the fuse, it did not pop like it was a major short. You could barely see the split in the link. Seems to be working fine now.