RV Air Conditioning Question

We have a 2004 Jayco 5th wheel trailer with an air conditioner that cools us and then waits a long time before it starts up again.  We are cooled then hot.  We have asked our local camper sales and service to help, but they say there is nothing they can do.  Do you have any suggestion, or do you think  it just the nature of the beast? Kathleen, (email)

Kathleen, it really depends on the type of thermostat equipped with your air conditioner. I’m assuming you have a roof top air conditioner. Some units have the thermostat located on the interior shroud of the air conditioner itself, while others have a wall thermostat for both heating and cooling. It’s possible either type of thermostat is out of calibration. If you have a wall thermostat, be sure it’s mounted about half way up the wall. If it’s mounted too low, it will take longer for the sensor to pick up the fact it’s getting too warm in the unit.

If the thermostat is located inside the air conditioner ceiling cowling, be sure the sense probe is not contacting any other metal component and that it is clean. Oftentimes, cooking oils or cigarette smoke can coat the tip of the probe, thereby lessening its functionality.

Here’s a picture of the sense probe. (You’ll have to remove the ceiling cowling to locate it). It should be positioned directly in the flow of the return air to the unit and not be touching any other metal component. It should just hang there, sensing the air returning to the air conditioner.

Also, be sure the thermostat is turned all the way to the coldest setting. If the unit indeed eventually cools the coach, the air conditioner itself is probably okay. Some thermostats are also adjustable. And there are additional tests that can be performed before fully condemning the thermostat, but these are better left to the professional RV service technician. Let me know the brand and model number if you need any further assistance, but check the position and cleanliness of the sense probe first and be sure it’s turned to the coldest setting.