20 Most Recent Dometic 57915531 Air Conditioner - Page 3 Questions & Answers

Look from inside you should see a filter and behind it a coil, the filter and the coil should both be clean, (very clean) might be all that's wrong.

Circulate fresh air around in the RV will solve the problem from returning, you will have to clean up what mold you have now.

Quite often if you hear clicking at ceiling assembly when you move thermostat at wall to fan, cool etc, but it does not come on, it is a lack of 120VAC.( hydro) Check all hydro breakers and have voltage checked at ceiling assembly as well.

The best place to get your 12 wire is Lowes and Radio Shack.

There are 6 wires to the thermostat. That are :--- 1) Red -+7.5; 2) Yellow - cool; 3) White-furnace; 4) Blue-hi fan; 5) Brown - fan and , 6) Green - ground. ------------ When this problem of compressor starts, at that time try moving the white wire or loose the screw for yellow wire and then see, is the compressor running or does it stops. ----------- If the compressor stops running, that means the thermostat is faulty .But if still the compressor is running with yellow wire unplugged from its screw, then there is wiring issue.The short is triggering the compressor to turn on.----------or its faulty relay in the lower control box.------- Most probably its faulty thermostat or loose wire .Remove the wires clean them properly and re-connect then check, before going to replace thermostat.--------- This should help.Thanks.Helpmech.

Look on the unit manufacturing tag it will tell you what kind of refrigerant it takes. If it takes r-22, you can't usually buy it over the counter. 134a can be bought over the counter. Definitely sounds like you are a little low on refigerant.

I would replace the selector switch and see if that doesn't fix your problem. Thank you.

Can you give us some more helpful information-- so we can help diagnose the problem:
Like-- what is the outside temperature?--

Have you been able to get heat out of your heat pump before, at this low of an outside temperature?

And which fan are you talking about-- the inside fan, or the outside fan?

Is the inside coil getting nice and warm-- or just barely warm?
and is there frost on the outside coil-- Can you defrost it, but shutting the unit off until the ice is cleared?

Let us know, and we'll better be able to help you to the next step.

Mack B

I am sure if you call the RV dealer or RV manufacturer they can tell you what type of AC is installed.

Its hard to tell from a distance, but when a compressor is locked up, it will attempt to start about every 2 minutes. It will draw a lot of current for a few seconds then click off. If this is the problem it requires a compressor replacement. As a last resort you might try a "hard start kit" which is available at heating and air supply companies. You may have to get someone in the business get it for you, they don't usually sell to the public.

most air conditioners have a low pressure (and high pressure) cutout switch. What this means is that when there is too little (or too much) freon in the system the switch will cut off the compressor saving it from damage and only the fan will be running. After a few minutes when the pressure equalizes the compressor will kick back in and the whole process just keep repeating over and over. I suspect you have a freon leak somewhere dropping the pressure in the system. Honestly I don't know if you particular AC is user serviceable where you can add freon yourself. If so, you can purchase a can of freon, they now come with the gauge attached so you can tell immediately if it is a low or high pressure situation, and some of the brands of freon have leak stop additives as well as compressor oil. Just make sure you purchase the proper type of freon, there are two main types, the older is r12 and the newer type is r134-a. it should say somewhere on the inside cover or on the compressor itself which type is required. Otherwise if you don't want to go through the trouble a reputable AC service professional should be able to tell you exactly what is wrong after connecting the gauges and they even have leak detector material to help them find the leak. Shop around, I bet it will be not much to repair and certainly cheaper than replacing the whole unit.

If you don't here the compressor kick in after about 3 min then the thermastat is not telling the compressor to com on, or the control board is not telling the compressor to come on. The power can be traced from thermastat to the control board and will have a 12volt feed on the yellow wire at the control board with compressor mode on. From there it is 120volts the control board has a relay that turns on the compressor. the compressor capasiter can cause the compressor not to come on, normally it will have burnt wiring.

Hi,

Here is a tip about troubleshooting your air conditioner...
There are many things that can cause your air conditioner not to cool…

Air Conditioner Trouble -Review the Possibilities
http://www.fixya.com/support/r3571569-air_conditioner_trouble_review_the_possi

heatman101

When you say your fan runs do you mean on the furnace or the outside unit? Double ck your themostat wires if you have a volt/ohm meter ck for 24 v at the contactor in the ouside ac unit. On most A/C units you can manually push the contactor in to make it contact be carefull 220v use an screwdriver to do this and push only on the plastic center if the unit kicks on your themostat/wires/or contactor is bad my bets on the wires. good luck

You can buy cut to fit foam or ridgid air filters at most hardware stores.

Could be a capacitor blown or over load burn't on the compressor.

There is a clicking at the control board, but is there 120 volts at the control? that needs to be confirmed. And is the plug from the upper unit to the control board plugged in? check for 120 volts.

If the the power is going thru the relay then we have a 120 volts. I would be looking at the neutral and ground to make sure, I have those. Its very unlikely that the fan and compressor would not work unless you were missing the 120 volt or neutral and ground. the problem could be in the breaker box as well. check for a loose or burn't neutral.

yes there are two capacitors and some times have stored electricty in them. you can get them from a RV parts store or you can take them off and have them matched at a electrical parts supply store. the MF is the important number on the capacitor to match.