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Motor home AC not cooling

The AC in my motor home sounds good, blows well, seems to be trying to "kick in" when switched from "fan only" to "cooling" but the air is no cooler when on "cooling" than on "fan only." I checked from below in the motor home and above from on the roof, and could not find any access points (valves or service points) in order to "charge" the system. It acts just like a car AC system that is low on "freon." Is there a way to "charge" the system? Is it possible to put "valves" or "service points" somewhere in the line in order to recharge the system? Does my rooftop system use "freon" like the AC in the engine of the motor home or does it use a different chemical? This is a 1993 29' Jayco motor home with the original basic rooftop unit. I would appreciate any help anyone may have. Thanks, Glendon Widrick

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The only service ports that you are likely to find would be on the unit itself on the roof. I would imagine you'll probably have to open an axcess panel on the unit to get to these.

As far as what kind of refrigerant is in these usually that same axcess plate will tell you. I couldn't tell you right off hand but usually its r-410a or r-407c. Occasionally you'll find one with r-22 but again it's up to the manufacturer.

But before you decide to try adding refrigerant keep in mind that legally this should only be done by a qualified service person. Not to mention that there could be a host of electrical or mechanical causes for this. Adding freon is not always, and most typically never is, the problem.

Yes this could be caused by low freon but again, if that's the case then it is most likely leaking and will need to have the leak repaired. This could also be caused by, but not limited to:
- a bad thermostat
- a bad relay
- a bad compressor
- a malfunctioning expansion valve

In summary I would highly recommend not trying to do this one yourself without the proper tools. You may very well end up causing more damage than you solve.

Posted on Jul 30, 2009


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