ac compressor runs constantly

[Ducter]

Just finished replacing the heater core, had to also run a new vacuum line to the control unit and got all the settings working correctly, put in a new blower resistor and now that everything is actually turning on and functioning the stupid ac compressor runs all the time, regardless if it's on ac, heat, defrost etc. Anyone have any idea what's causing that?

 

[EXJAY]

Id first disconnect wires at the compressor and run the motor to see if the clutch is possibly seized in the engaged position causing it to run no matter what position the controls are in. If it wasnt doing this before likely something with the new wiring is shorting or with the controls etc telling it to run.

What year?

 

[Ducter]

It's an 89. Not real sure if it was doing it before as I just got it a few weeks ago. The blower motor wasn't working I was told and until today I hadn't messed with it. Replaced the resistor and the motor works now. Not real sure where to go from here.

Thanks

 

[Blue85]

There are 3 things I can think of.
1) The clutch cycling switch is stuck (on the side of the receiver/dryer).
2) The mode switch in the dash is broken. These use plastic to cover the metal on "non-A/C" modes. The plastic can break or wear away, exposing the contacts in other modes.
3) Pinched wire somewhere.

Here's the easiest troubleshooting steps (do one at a time):
-Pull the fuse
-Unplug the connector on the clutch cycling switch
-Unplug the connector on the compressor clutch.

 

[Ducter]

Alright, thanks. I will take a look this evening and see what I can figure out.

Thanks again