[alanmay0]

For some reason the 12v wire going to my ac compressor is only 9v which is causing the compressor to NOT engage properly. Does anyone know why I would only be getting 9v? Does anyone have the wiring dirgram just for the AC?

Does anyone know where the wire that runs to the ac compress comes from?

thank you in advance
alan

[steve25]

Unplug that clutch connector and if the full battery voltage then shows up at the connector your clutch is partially shorted, or the wires going to it are leaking current.

The clutch is allowed to ingauge by the pressure switch which cuts out the clutch above 4200 rpm or so.
This means the pressure switch overrides your A/C on off switch in your dash board.

[alanmay0]

Thanks I was testing the compressor wire, the one in the wiring harness that runs along the top of the drivers side valve cover, about a foot away from the compressor and with the ac compressor running it was giving me 9v. Now if I took a wire and ran it from the battery to this compressor wire, at the same location I was testing it at, the compressor would work correctly. So it looked to me as if the black compressor wire I was testing was not getting the full 12v needed to run the compressor. I will check as you suggested but doubt this is the problem. Still need a wiring diagram of JUST the ac. Do not need the huge wiring diagram of the entire car.

thanks again
alan

[OG68]

Master Relay not energizing or mis-wired. If the master relay is not energizing, clutch will receive voltage from the heater motor resistor which lowers the voltage preventing clutch operation.
Check the 30 amp fuse. Schematic is from a 68 but should be similar to your 67 (which I'm assume is the car we're discussing)

[alanmay0]

thanks