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joraz's avatar
joraz
Explorer
Jul 17, 2022

Roof A/C Issue

Class C with a 13.5 Dometic (Model Number: 520316.506E) year 2009


My rig is parked at the house in the hot Arizona sun. The A/C works fine for most of the day but when the ambient temp hits 104 or so the compressor shuts down and the fan blows hot air.

The A/C has had little use over the years. I cleaned both the evaporator and condenser coils although both were already very clean.

The unit is draining as it should and the interior filters are clean.

I did a voltage check over the day yesterday and have eliminated low voltage as the problem.

I have been advised on another forum that the issue could be the overload protector (thermal switch) which is designed to shut down the compressor when it's too hot. So I figured I would just replace it. Problem is that it looks to be internal to the compressor.

Any ideas? Thanks.
jor

Compressor Photos
  • I am dragging up old memories here, so there may be other problems. I replaced a number of over temps that were in the terminal box that was held closed by a spring, and most of those were held against the side of the compressor by a flat spring that dogs into said box.

    If yours is like that, you may be able to change out the over temp switch. The trick is going to be getting a replacement. That sure is not a big box or hardware store item. Look for a refrigeration parts place or a Grainger.

    Best of luck.

    Matt

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