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Paintblend · 09-23-2010, 04:13 PM

i own a 1996 mountain aire,(which i love) 38 ft gasser 460 ford, i have noticed the dash ac is not as cool as it once was,, and then i noticed the compressor is on all the time,, the only way to shut it off is to unplug it,, the little blue light on the dash stays on even when the ignition switch is off,, and when the engine is running, the compressor stays on all the time even if you push the ac button and the little blue light goes off the compressor still runs,, the mechanic wanted to know if i had a wiring diagram,,, ha ha ha ha ha,, i said no but maybe some of my newmar friends have one or know of such a problem,, the freon pressures are good, the compressor is operating, and water is condensing from the big box on the firewall,, but why is the compressor on all the time,,, you can hear it click on when you turn the key on even when the ac dash switch is turned off,,
any and all help or opinions are welcome
thanks
steve

Good man · 09-23-2010, 04:50 PM

Paintblend,
I suspect you have a relay which is stuck in the closed position. You may be able to trace the relay from the wiring which comes out of the fuse panel for the AirCon circuit.

It is supposed to react to the demand for the compressor either by the A/C or Defrost setting on the controls. If you can locate it, you can unplug it and see if your compressor stops constantly running. If so, you can substitute another relay of the same number from some other non-critical system to verify before buying a replacement, although they are not very expensive. (Spares are a good thing to have.)

There is no way I can tell where to look for this relay, but the color scheme of the wiring from either the fuse, the A/C switch, or the compressor itself may lead you to the correct relay. It is usually a small black cube (about 1" X1") with 4 or 5 blade plugs and it fits into a gang box containing similar relays.
Good luck,
Jim

Paintblend · 09-23-2010, 05:42 PM

i found a box of those square box relays on the drivers side of the firewall,, i unplugged them one at a time and two of them killed the engine and the other two did not turn off the compressor,, i will keep looking,, it is difficult to trace the wiring under the dash but a mans gotta do what a mans gotta do,, i will keep looking
thanks

Good man · 09-25-2010, 11:24 AM

Quote:

Originally Posted by Paintblend

i found a box of those square box relays on the drivers side of the firewall,, i unplugged them one at a time and two of them killed the engine and the other two did not turn off the compressor,, i will keep looking,, it is difficult to trace the wiring under the dash but a mans gotta do what a mans gotta do,, i will keep looking
thanks

Paintblend,
You say that you can "unplug" the compressor and it will stop running. This rules out a "stuck" clutch which will not release the compressor. OK...

What you can do is to start from the compressor wiring which is energized when the ignition switch is turned on to activate the clutch... and work "upline" toward the relays, switces and fuses until you can identify a relay or switch which is frozen closed. You should be able to do this without the motor running... much safer if you can.

You can use the wire markings to help you trace through looms, but bear in mind that sometimes these schemes get changed when work is done on a system. It is also possible that the A/C clutch wire is melted and fused to a "live" wire inside a loom.

Persistence, patience and curiosity... will pay off! (Easy for me to say in the comfort of my den!

Good luck,
Jim

Paintblend · 09-26-2010, 08:00 AM

excellent idea, i will try that today,, i can hear the clutch click on when i turn the ignition switch to on, even if the ac is turned off,, it should not do that ,,,right,,, so there has to be something feeding it power all the when the switch is on,, i will start the evil trace and see what i can come up with,
thanks
steve