Here is the deal.... I had a bad compressor in my 300D (old one
leaked, but still worked), so I changed it. Now, it does not engage.
I have checked/changed/bypassed the low pressure switch, fuse (blower
motor is on the same circuit and operates), changed the push button
control unit, verified the system pressure, but nothing. I placed a
multi-meter to the compressor wiring and I do not see 12V at the
I see that there is a AC Comp relay that was used ONLY on the 85 300D
and 300SD. I do not have a spare relay to test with. This relay is
next to the brake booster (I believe the earlier ones used the small
silver "Ice Cube" relay under a panel on the drivers side wheel well.).
I do not want to spend $300 and find it is not the problem!
Any ideas???????? It is going to be 90 here this weekend!