Bedroon AC problem?

GlennWest · 05-30-2010, 04:32 PM

Today my bedroom AC quit. The thermostat had no display for bedroom ac. I shut down all power to RV including battery disconnect. Rebooted everything and display came back on thermostat. Ac unit still not working. After about 5 minutes it came back on and display also working. Anyone else ever had this to happen? We have been having some issues with the thermostat. Wife messes with it a lot. Have it turned too low and then change it to higher setting and it won't respond, just keep running. Will have to shut down unit with switch and restart to get it to work. ????????

GlennWest · 05-30-2010, 04:36 PM

update. Just went back out. Display blank, except for numbers 1 2 at bottom. Turn to AC 2 and display working and ac running. Just no front ac or display.

GlennWest · 05-30-2010, 05:10 PM

Well, it's back on now. ????????

GlennWest · 05-30-2010, 05:59 PM

Off again. Is this just AC related? The thermostat going blank had me questioning.

Motor31 · 05-31-2010, 10:09 AM

New one to me. Have you tried the tech support line from Dometic? I hope it's the thermostat as that is the cheapest item to replace.

jdwilson3 · 05-31-2010, 10:20 AM

Glenn, when we traded off our ES, we were using AC units number 4 & 5! Use caution when calling Dometic...they told me I had a bad thermostat and I drove 88 miles one way to get a new one, but the issue was the front AC was bad, and I had to disconnect the phone cable between units on the roof. Price of the thermostat was $88 at CW

GlennWest · 06-06-2010, 10:07 AM

Can anyone walk me through checking the capacitor in my duo-Therm 15K heat pump? I'm thinking it might be the run capacitor going bad.

Carny Bill · 06-06-2010, 12:39 PM

to check a cap.....use an ohm meter, best is an old style analog, but digital will work. put the probles on each of the cap's terminals. Reverse the leads on the terminals. Everytime u reverse the leads the meter should jump from a high resistance reading and drop down to a low.

If meter reads a high resistance all time, the cap it shorted. If it gives no reading it is open.

Hope this helps and good luck....Bill

GlennWest · 06-06-2010, 02:18 PM

Thank you. Will let u know what I find.

GlennWest · 07-24-2010, 03:41 PM

Can I check this with it running or do I need to kill all power?

RonS · 07-25-2010, 12:21 AM

Glenn - I dont have a clue on your AC issues. But I can offer what I found out when my capasiter went out each time (twice). Each time the thermostat was working, but AC would just not kick in even when set way down to 50. First time I could smell something like rubber burning, second time no smell. However in each case when I took off the AC cover I could see that the capasiter was fried and the wires were all chared. The last time I changed the capasiter Dometic had sent me an updated version and it has been working for over a year. However a couple of times the AC would not cycle I had to mess with the thermostat to get it to kick in. Having said all this I think you can tell if the capasiter is bad just by looking at it.

GlennWest · 07-25-2010, 07:50 AM

Thanks, nothing appears burnt. I took the cover off to look at the circuit board yesterday to see if any connections were dirty or loose. Everything seemed good. Came inside and removed thermostat from wall and pushed the rj11 connector in further. Surprise!!! So far so good. Has not shut off since. Suppose to be 104 today. Will report back if fixed.

Motor31 · 07-25-2010, 10:39 AM

The capacitor is a one condition item. If it's bad it will not work at all. If it works, it's not bad.

I had the same symptom as did Ron. when the capacitor fried I had a strong odor of burning insulation and a loud hum from the AC compressor. Continuing to try and run the AC will likely result in a fire in those conditions. Replacing the capacitor is not a big deal and there is little you have to remove under the cover. My tech has gone though the route with Dometic many times. He found that the Coleman AC units used a residential grade capacitor that is more robust. Dometic seems to have agreed as their new replacement units look identical to the Coleman ones. I went through 2 capacitors on my main AC / heat pump unit before going to the larger capacitor. It's been 3 years now with no problems from it.

You need the capacitor to send the big voltage spike to get the compressor turning as it takes a huge amount of juice to start. Once running it's fine.

Carny Bill · 07-25-2010, 10:45 AM

Sorry I just saw ur post. U will need to shutdown power to the unit when checking the capacitor. U are checking Ohms (resistance) not Volts.
Good luck, how the loose connector did it. I just lost my front ac unit last nite, it made quite the racket before totally quiting.

GlennWest · 07-25-2010, 04:08 PM

Working great now. Had to be that loose connector. Didn't go in much at all but it was enough. Thanks everyone. God bless.