9400i a/c problem

Your truck will have two high pressure switches. Sorry, I gave you directions for the wrong one. The one near the compressor is for the fan. The switches you are looking for are under the heater box under the passenger seat. The switches are actually outside on the underside of the bottom of the cab, under the heater box. You will see where the a/c lines travel under the cab and go into a little black plastic cover. Inside the cover is the expansion valve and the high and low pressure cut out switches are mounted on the valve. For your circuit you would need to unplug those switches one at a time and see if your a/c starts to work. If either the low or high pressure switch is closed it will trigger the a/c compressor relay and cut power away from the compressor. The power for the compressor goes through the freeze switch, so you would also need to test for power through that too.

 

I would check the freeze switch next. it's located under the passenger seat. two green wires going to it and has temp probe that goes into the evaporator. with a/c on unplug both wires and install a jumper. also check for power there before you jump it.

 

sounds like a bad wire between the freeze switch and compressor what year 9400I?

 

So. .is the door opening? I had to manually move mine a couple times to switch between heat and air for awhile. But none the less its a very easy fix.

 

check the harness that crosses over the valve cover they often rub there. your looking for green wires i believe.