Dometic Heating & Cooling - Recent Questions, Troubleshooting & Support

I was replacing a DUO-Therm 3105058 Rev A. very old Thermostat in a Coachman RV with 3106995.032 from Amazon. After looking all the information on the directions it was clear I would have to play a hit or miss on some of the wiring. Instead of using the same coding, such as RC, RH, G, Yellow and such. they used the function and I had to guess at some.Here is the wiring I found worked:There are 6 wires. One set of two wires (white On the W & red on the RH) and the set of 4 (yellow On the Y, green on the G, red on the RC and blue on the H). So to keep it simple the red on the RH went to the +7.5. The White on the W went to the FUR. HS/HP not used. the Yellow from the Y went on the cool. The green on the G went to the fan. The red on RC went to GND. and the Blue on H went to Hi fan.So red (RH) of the 2 wire goes to +7.5White (W) of the 2 wire goes to FUR.Yellow (Y) to coolGreen (G) to fanOrange or red from the RC lug goes to GNDBlue (H) goes to Hi Fan

check amp draw either bad compressor or fan motor

it draws locked rotor amps at power application. capacitors boost it quicker then you read it if all ok then runs at full load amps.

Same problem...then discovered my thermostat was set to Celsius instead of Ferinheight... pressed toe temp up and temp down buttons to change..fixed...

sounds like duct damage or restriction in duct work.

Sounds like the wires are for fan and are supposed to go to a capactor I’m happy to help further over the phone at https://www.6ya.com/expert/vincent_f7b7c5f4dedd2565

possible heating element bad

check compressor relay possible stuck on

get it serviced

Call for AC / refrigeration service, it needs refrigerant gas and needs to be checked for leaks. https://www.google.com/search?q=Dometic+Duo+Therm+short+cycles ..

make sure thermostat on auto possible start up capacitor on compressor

Need to look around and should have an error code and give more detail of what the problem is. If you post that i can maybe help you more. I need to know......

check and test compressor relay and circuit

if power to unit and thermostat is calling for action then check start up capacitors

Start simple, verify proper voltage. Check capacitor. Then check motor.

some awnings have a sensor that retracts the awning if wind elevates to certain level. i wish mine did. i have seen them ripped off rv's.

no info -look in your paperwork for your trailer unit and the mystery a/c unit and look up the trouble code in owners manual --notify jayco of problem --do online search of a/c using make and model for trouble shooting guide - rv shop

https://acerrorcode.com/dometic-thermostat-error-codes.html

So original was ecm and you’re installing psc?? All low voltage speeds will go away and you just need to break the new, high voltage speeds, with a relay. Hope that helpsI can’t find info on the 135a. Does it have a control board to land wired to?? What model motor???Can’t make out the original wiring diagram. The white is your common or neutral. The different speeds are for constant fan speed, cooling speed, and heating speed, this is your hot. Not sure if you have a control board in your unit but if you do it will say “common/ fan/ cool/ heat/ park for places to land your wires. The browns go to capacitor and the orange and purples would get swapped if it were running backwards. ( meaning blowing air out of filter rather than pulling air through filter. Zip tie loose wires to prevent getting caught by wheel.

On a single phase universal motor with a start and a run capacitor, that is handy. The start capacitor is fully automatic as there is an internal centrifugal contact that breaks the contact when the motor reaches near running speed. The run capacitor puts one of the motor windings out of phase with the other and determines the direction. Placing the run capacitor on the neutral will make the motor go the other way than on the live.