No A/C

[Garristl]

Hey Guys, I have M4070 cab heat/AC 4x4. I have checked all my fuses and all is good. How ever there is no power going to my A/C clutch. My low pressure safety switch omhs out to be good. It also has 12 volts going and coming from it. If you put a jumper wire on the battery to the clutch it starts working and cooling. but I can't see why I have no power is getting to clutch with all four fuses good.
Any ideals?
Thanks
cowdog

 

[85Hokie]

if you bypass the LPS ...what happens then?

If you measured the continuity.....that says you just have a closed loop - but it might provide enough amps to start that clutch!

Can you place the same jumper at different point in the circuit to bypass each piece?

 

[Jim L.]

To troubleshoot this easily you need a Workshop Manual (WSM) for your model. It will have wiring diagrams to help fault isolate.

It is likely that there is a compressor relay, a pressure switch(es), a sensor for evaporator icing, and a control amplifier. These are the components to check out using the WSM.

 

[mickeyd]

Welcome to the OTT forum Cowdog. You came to the right place to get answers.