hey guys,
my a/c compressor wont engauge, so i checked it out today, got lots of charge in it, i have pwr on both sides of the low psi cutout switch, no pwr at the clutch, the ground is good, just no pwr, when i jumped it with a hot wire, it kicked right in. soooo i have checking everything i can think of, swapped out push button control with a known good one, didnt help, does anyone know the location of the "compressor relay"?? have not been able to find it. also the tack has been working spuratically lately, i read where there is a relay that controls both??? would that be the compressor relay??? need a physical location on this baby!!!
thanks
matt

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matt

You checked the low psi switch which takes the system off line.

Did you check the high engine temp switch which also take the compressor off line in event of an overheat? There's also something that detects a belt slip that also takes the system off line.

Why are you changing the pushbutton unit if you have power on both sides of the pressure switch? You're troubleshooting has almost gotten you to the problem. Trace the wire from the clutch backward toward the pressure switch. If it goes through a temp switch as DZLPWR indicates, then check both sides of that switch. You're almost there, don't get off track in the process.

Good luck,

found the problem!!!
relay box p/n 001 545 74 05, only 85 300D's have them, sets behind the relay box on the left fender well, has a multi purpose function, one of which is the a/c magnetic clutch relay. pulled it out and took it apart, has a land burned up on the circuit board, repaired the land still didnt work, must have wiped out a componet ont he board also, i can manually push the relay and a/c kicks in, will have to bite the bullet!!! these things are around the $200 mark!!!! ouch!!!!!
thanks for the help guys!!

__________________
matt