Top 20 Dometic 57915531 Air Conditioner Questions & Answers

Make sure the mode is set to freeze and temperature is set to below the room temperature. If it is a split system, check the outdoor unit whether it is running. If it is running, see if you can reach and feel the temperature of the pipes connecting between the indoor and the outdoor unit. It should be cool. If it is not cool, you may need to get somebody to check the refrigerant.

could be or the compresor is going off on a safety. replace run capacitor.

condensor straight water, evaporator they make a solution that you spray on and continue to run in cooling it self rinses.

compressor capacitors, thermostat, relay module, bad compressor, lost charge of freon.

with a good start capacitor you will not have time to read starting amps. it should drop to running amps almost instantly.

Any rv dealer either stocks them or can get them for you

take amp draw and multiply it times voltage to give you watts.

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.

should work

multiply the amps on data plate by voltage applied its watts

Fan coming on at converter will be directly related to load on the converter. If no lights etc on, the fan will probably shut off, but start turning on lights and it will come on. Normal operation, as it it just the cooling fan coming on under load to prolong the life of the converter.

duct work became either blocked ,un done or damaged.

Up to 24 ft, use 12AWG copper, with 20 amp breaker. Recommended in manual.

I had the exact same problem, duo-therm AC unit on my RV the compressor ran continuosly, had to shut it off at the breaker. I too replaced the relay board thinking it was a stuck relay but the problem was still there. Good news is I found the problem. I took the cover off the thermostat panel inside the coach and found the thermostat wire marked "cool", was loose. I tightened this connection and the compressor shut down. Looks like the compressor and fan use seperated thermostat wires. Easy fix, and now I have a spare relay board that I didnt end up needing in the first place :-) Solution= check your thermostat connections at the terminal block inside your thermostat panel, they are probably loose.

you either have a bad run capacitor or low on coolant and you pressure switch isnt letting compressor come on

Usually blocked filters but can also be set too cold.

Normally that would be a closed/sealed system, not rechargeable, from the factory. Don't know what valve your seeing, unless someone has retrofitted it with valves for recharging prior to you purchasing it. I will say that quite often the reason for poor, or less cooling, than when new, is often due to simply needing a good cleaning of evaporator and condenser coils and fins. Has that been done lately?

HelloOne quick way is if there is a sight glass on the liquid line or small copper line,you will see liquid freon in the glass.This means there is freon,but you need to put a set of pressure guages on the system to be accurate.usually if your low on freon the system will freeze up and then afterwhile do nothing.Suggest having a service person comeout to check the system for a proper amount of freon charge.

Sounds like your drains for drip pan under the evaporator area are plugged. They are located at the base of the AC unit on roof. Look real close under AC unit near front, for a hole in base plate of AC on each side. Water ( condensation ) should be dripping out of those holes pretty steady when running.
You should have an inch or so clearance between base of AC and roof to try and get a bent piece of wire, or similar in to hole and try to clean it out. If that doesn't help you will have to remove plastic cover and remove all the screws that hold the front cover over the evaporator and remove the front metal cover. Look down at base of the coils and fins and you will see a drip pan that has small holes at each end for drainage. They will get plugged up with debris, thus poor, if any drainage. I use a long air nozzle and a small compressor to blow them and the tray out to clean it well. That will usually cure your problem. Please remember to shut all power to AC, off at breaker panel before removing the cover on roof to avoid electrical shock.