Issue with my AC.

[KcBorne]

I am having a strange issue with my Dometic Duo-therm AC in my Cavalier TT. The compressor does not want to kick on when it gets hot outside. The unit works fine for the majority of time but when the sun is at full force between around 12-4pm (when i need it most) it doesn't want to come on. I bought a Duo-therm analog AC control kit and replaced the old one yesterday but apparently that was not the problem. Does anyone have any idea what might be causing this kind of issue?

[KcBorne]

Thanks for the info. Free is best!

[Tequila]

For reference, there is a sensor attached to it. I found when mine would not run in the heat, it was the cause. It is a thermal overload protector. If the A/C is running too hot hot it will shut it down. If it is faulty it will shut it down prematurely. I cannot remember exactly what it looked like but it was black & round and had 2 wires attached to it. It was cheap to replace.

It looks like this

[marcsbigfoot20b]

Its great when you fix something yourself......for free!!!
:C

[KcBorne]

I was able to get it fixed. Turns out it was a dirty condenser. It had about a 1/4" layer of build up on the inside of it. Thank you to everyone who commented and helped me solve the problem.

[dbbls]

On the older round Dometic thermostats, they will not work if the temperature of the thermostat is over 100 degrees. To get them to work, hold a bag of frozen peas against it to cool it off. A bag of frozen corn will work just as well. Once cooled down it should work. If the trailer has been shut up it can get over 100 degrees in there.

[KcBorne]

Thanks for the replies. I got out the ladder to check it out a it started raining. I will get up there tomorrow and give an update when I get it cleaned.

[RV_daytrader]

marcsbigfoot20b27 wrote:
So it starts up but won't continue when it's hot....
Sounds like possible condenser fan problem on top, or condenser may be dirty causing high head pressure when it gets hot outside and the unit shuts itself off to protect itself.

I agree with the dirty condenser being the cause...plus it's an easy fix if it is the problem....brush off surface dirt and use compressed air to blow dirt from between fins.

[marcsbigfoot20b]

So it starts up but won't continue when it's hot....
Sounds like possible condenser fan problem on top, or condenser may be dirty causing high head pressure when it gets hot outside and the unit shuts itself off to protect itself.

[KcBorne]

There is no humming or pause when it it cycling on/off. It has came on about about 4 times since I started this post. It only stayed on for a few minutes each time. Not even long enough to drop it a degree in here. I don't get it because it will run all night without a problem.

[marcsbigfoot20b]

You can pull the cover on top and see if your unit came without a start capacitor. Some do some don't. $20 fix and super easy install.
Is it humming then kicking off or not even trying?

[KcBorne]

I have it plugged in at my home. We do tend to have a few brown outs every summer in my neighborhood tho. This 95º Louisiana weather has everyone's AC wide open. I will try to check a few times throughout this evening and see if anything changes.

[KcBorne]

Thanks for the try. 88º Inside here.

[2oldman]

117 is ok.. the voltage is virtually the same everywhere. Did you measure it in the hot afternoon? Can you measure it when the a/c is trying to run?

If you're in a crowded CG with other rigs running their airs, that could mean the voltage is sagging badly. Other than that, I have no idea.

[nomad297]

2oldman wrote:
What's the voltage at your rig?

Good question!

Bruce