Dash a/c?

There should be two wires coming off of the compressor. All you need to do is tap in to one of those wires with a needle type meter probe and feed in 12 volt power from any place that is convenient. You do not have to have the engine running to tell if you have picked the right wire. You will hear the compressor clutch engage and disengage. Once you know that you can energize the compressor, then you can start the engine and try adding freon. Make sure that you are doing all of this away from any fan or belts that could grab you and ruin your whole day.
Obviously this is not the preferred method of repair but it may get you through this crisis.
There may actually be only one wire, if they are using the compressor case for ground. In that case it is easy to pick the right one.

I cannot get there. The compressor is high on the engine, I can barely see it. Certainly cannot reach it. Top access would involve removing the huge mirrored closet doors, emptying the closet, removing most of the t doorway trim, and finally being able to access and remove the hatch. Something I'd do if/when I decided to change the compressor, but not before.

Does anyone know for sure if the compressor is controlled directly by the dash controls and safety switches?
Or is it controlled by the ECM (like many newer cars are)?

This is an '08 Monaco entry pusher, cummins ISC, rear radiator.

would be really happy to lay some power to that clutch from somewhere outside the engine compartment.

JimM68 wrote:

donn0128 wrote:
If the compressor wont engage, then your problem is not low of freon. Take it to a real AC service tech and have him fix it.

All modern automotive A/C systems have a low pressure switch to prevent the compressor from eating itself running with no refrigerant. Just need to know where the switch is and jump it out. (I think)

Besides I have loads of reasons for fixing it myself, starting with "that's what I do" and then "I really don't have the spare cash right now to pay a shop to fix it" and finally "we are fulltimers, with 3 adults and 3 dogs living in this coach, currently camping in the middle of freeking nowhere"

Please note, people don't post on a help forum to hear "take it to a shop"

But thanks for your help.

The OP is correct about a low pressure switch. The control that you jumper should be right on the clutch with a couple of wires coming off it. Mine has a push on spade that I remove and put a 12 volt line onto. Clutch will engage. Make sure you are on the low side!!!

donn0128 wrote:
If the compressor wont engage, then your problem is not low of freon. Take it to a real AC service tech and have him fix it.

All modern automotive A/C systems have a low pressure switch to prevent the compressor from eating itself running with no refrigerant. Just need to know where the switch is and jump it out. (I think)

Besides I have loads of reasons for fixing it myself, starting with "that's what I do" and then "I really don't have the spare cash right now to pay a shop to fix it" and finally "we are fulltimers, with 3 adults and 3 dogs living in this coach, currently camping in the middle of freeking nowhere"

Please note, people don't post on a help forum to hear "take it to a shop"

But thanks for your help.

If the compressor wont engage, then your problem is not low of freon. Take it to a real AC service tech and have him fix it.