A/C compressor issue

[ColRon]

I have a Dometic Cruisair STQ16 A/C in My Salon. The other day, it was in cool mode and quit normal operation. I found it was showing 98 degrees on the Thermostat, the water pump and fan were running and water was flowing, but the compressor was not running and it was not cooling. the actual inside temp was around 55 degrees. I turned the unit off. I turned the unit off and then turned it on to the Auto mode. The heat cycle kicked on and everything operated normally and it began heating the salon to the set temp of 70 degrees. The following day, the unit kick off again and the compressor was not running, but the fan and water pump were running.

What I have found... When i turn the unit on everything seems to work as normal, the fan comes on, I then hear a click and the water pump starts and then I hear a click for the compressor, however the compressor does not start. Water flow is good, and there is no air handler blockage. I have ran both a low and high pressure switch test at the controller and both report ok and no errors. From what I understand, it the unit is low on freon, I should get an error from the low pressure switch. I also did a system reset at the controller, but no change in condition.

It problem appears to be related to the compressor, does anyone have an ideas on what to look for next?

[km1125]

Not sure on that specific model, but a lot of the compressors have a breaker mounted on the top of them that will protect against hi temperatures on the compressor or high current draw. Normally they would reset on their own, but it could be defective. They're called Klixon and you can do an online search to see what you'd be looking for.

But also clarify one thing in your OP... in the first paragraph, it sounds like when you reset it then it will run OK for some time and then stop working, but the second paragraph is sounds like it's not working at all now.

[Viper]

When you hear the click that you think is the compressor trying to kick in, check the ammeter on your main electrical panel. If the compressor is trying to start, you'll see a deflection on the meter due to the higher start amperage. If you don't see that, the compressor may not be getting a trigger to start. There could be a few reasons why the compressor won't start; could be the compressor itself is on its way out, an electrical issue, controller, etc. I'd start with checking to see if the controller actually triggering a start. If it is, I'd start by checking if the start capacitor is okay. If applicable, it can be mounted on the compressor or in the control box.

[kgarguilo]

Have you checked the capacitor amd or control panel circuit board? Mine, albeit a different model has a dual run capacitor meaning, one side is for the fan and the other is for the compressor. Also, check your control board to see if anything looks burned up. I just replaced my control board. My issue was the fan which is why I looked at the capacitor first. Good luck.