Dometic Power Problem

[tbettes]

I have a 1960 Overlander with a fairly new dometic AC (4 years lightly used). We have not traveled in the Overlander for about 2 years and the AC has not been on since last summer or fall. I tried turning it on yesterday for a trip this weekend and the thermostat stayed blank. No power? There is power to the breaker that the AC is on and the breaker appears to work (I did not pull the cover and check). I checked that no wires were broken or disconnected at both the thermostat and under the cover on the roof. I am not sure if this is something simple or if I need to take it in. Any ideas??

Thanks
Tom Bettes

1960 Overlander
1962 Bambi

[tbettes]

Since I received no responses, does anyone have a trouble shooting guide for Dometic AC. I still want to believe this is an easy problem I can fix and do not have to take it into the dealer.

Thanks
Tom

[HowieE]

First thing is to verify that the unit has power. If the fan can be controlled separately try it. If the fan runs you have power to the AC. If the fan does not run check for power at the 120 volt connection above the ceiling plate. Disconnect the power as you open the connection and then have it turned on as you are about to check.

If you don't have power at the connection the problem is in the 120 volt supply. remove the breaker panel cover and check the output side of the breaker for power. If the breaker tests good and still no power at the AC the wire is open somewhere, not a likely problem but.

If you have power at the unit and the fan does not work the problem is in the AC.

If the fan did run in the above test but the compressor will not come on it may be time to go in. Does your AC have a time delay on start up? The older units often had a time delay of 2 or 3 min. to protect the compressor from restart after a short power failure. If you don't know wait with the AC on for at least 5 min. to see if it comes on.

[daveswenson]

The thermostat is 12 volt. Check fuses.

[PaulnGina]

I don't know the specifics of your thermostat but I'm just throwing this out there.......

Does the thermostat possibly have its own battery source? Maybe needs some double-A's or something?


PaulnGina
1987 Avion 34W
1995 Ford F250 7.3L PowerStroke

Not "lucky"....... BLESSED!!!!!!

[HiJoeSilver]

If it's a climate control center thermostat it has its own 12v supply. If you pull it off the wall you should be able to check for voltage. Check your 12v fuses.

[HiJoeSilver]

TS guide

http://bryantrv.com/docs2/docs/ccc.pdf

[lewster]

Originally Posted by tbettes

I have a 1960 Overlander with a fairly new dometic AC (4 years lightly used). We have not traveled in the Overlander for about 2 years and the AC has not been on since last summer or fall. I tried turning it on yesterday for a trip this weekend and the thermostat stayed blank. No power? There is power to the breaker that the AC is on and the breaker appears to work (I did not pull the cover and check). I checked that no wires were broken or disconnected at both the thermostat and under the cover on the roof. I am not sure if this is something simple or if I need to take it in. Any ideas??

Thanks
Tom Bettes

1960 Overlander
1962 Bambi

You didn't specify which Dometic control system you have for your A/C unit, but many of Dometic's digital electronic t/stats get their 12VDC power directly from the upper control board that is located under the A/C shroud on the curb side of the unit.

There is a 3 amp fuse located on that board. If your Airstream fuse that supplies power to the A/C is good, then I would look at the 3 amp fuse on the control board.

The other weak spot in Dometic's power delivery system is the cheap plastic RJ-11 unions that they use to connect the phone type data cable that runs from the back of the t/stat directly to the board.

The upper unit will have 2 black phone-type data cables hanging below the return air opening in the ceiling. Each will have a plastic RJ-11 union on them. You can use either connection point and switching it over might be productive.

Once in that reel, you can also check to see if the control board is receiving 12VDC control voltage by finding the red and black wires coming from the board and checking them with a VOM. you should see 12.0-13.6 VDC on those two wires.