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Tuesday, February 2, 2010

RV Air Conditioner Will Not Shut Off

We have attended your seminars at the Hershey RV Show for the past several years and now find ourselves needing an answer to a dilemma with our Newmar 5th wheel. The first summer we had this RV the Penquin air conditioner needed to be replaced because it would not cool. Last year we were using the air conditioner in the automatic mode and it functioned okay but when it came time to turn it off we could not turn it off with the on/off switch beneath the thermostat on the wall. However, we could use the Off Mode to turn it off. We had an RV repair company replace the thermostat on the wall, but that did not work. Then the repairman went on the roof of the RV, opened the A/C cover and tapped the contacts with the end of his screwdriver and that allowed the on/off switch on the thermostat to work. When the repairman left the A/C was switched off. Later that evening the A/C came on by itself and we were not able to turn it off at the switch, again. We contacted the repairman and he replaced the "motherboard" on the roof unit; however, that did not work either; the thermostat switch will still not turn the unit on or off. Do you have any recommendations on how to solve this problem? Joseph, (Mount Wolf, PA)

Joseph, it sounds like you may have some shorted wiring between the thermostat and the roof unit or an incompatible thermostat. Faulty boards are more common than they should be, however, a technician can use jumper wires to verify if new wiring on the control circuits between the wall thermostat and the A/C is needed. The temporary jumpers will isolate the problem to the conductors or to the board itself. The tech will also have to verify that the new thermostat is compatible with the air conditioner; not all are.

I wish I had more concrete info for you, but it without the wiring diagram and the part numbers, there’s no way to verify via long-distance. I’m not sure where in PA Mount Wolf is located, but I have a Master Certified technician in Eastern PA who might be able to help. Give Ron Donachie a call and see if he can make a service call for you. Here’s his contact info:

Ron Donachie
Ron’s Mobile RV Services, Inc.
Serving Eastern Pennsylvania

Thanks again for your email. Do let me know if Ron can help you out!


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