[Parisjet]

Had the rear AC stop working, the coach has the 4 roof top A/C units all controlled by the thermostat in the kitchen.

• I checked the capacitor and it is good
  
• the fan still runs
  
• the compressor kicks in for 5 seconds or so and is back off
  
• the compressor is warm to the touch
  
• the lines from the compressor are not cold
  
• the unit looks original from 2005
  
• Would this unit work as a replacement? Dometic Brisk II RV Air Conditioner 13,500 BTU - White B57915.XX1C0
  
• https://parts.unitedrv.com/products/dome...db881b19f8
  

If i replace with a new unit, what is the best one to buy
I don't like having just one thermostat in the kitchen as we like it real cold in the bedroom and warm in the coach. My preference would be a thermostat in the bedroom, any ideas of someone that has been down this road before. Thanks!!

[hypoxia]

I don't know what model you have, but, You "checked the capacitor". Does it have 3 terminals on it or two? Does it have another capacitor with a variable mfd (88-108 mfd or similar)?? Does it have a PTCR? Was the microfarad reading within 5% of the value stamped on the capacitor?

You may be up to speed on what you're working on but I'm new here and don't know your capabilities. Your symptoms are consistent with one of the above parts failure.

[afrench]

Put a tap on it and charge the unit.

[Richard]

I want to second what Jim said. If you don’t have a voltmeter, get one with both a clamp on ammeter and the ability to test capacitors.

Turn off the power, short the terminals of the cap with a screwdriver to prevent a nasty shock. Remove the wires, and test the capacitor.

If it is OK, then reassemble, turn the power back on. Clamp the ammeter around the compressor wiring (just one, not both) and read the amperage.

Somewhere on the compressor will be a label with LRA (locked rotor amperage). If you see amperage values close to that number, then the compressor is shot. You will spend more money trying to replace the compressor than a new unit costs unless you have that capability or know a friend who does.

If it just hard to start meaning the amperage is less than LRA but higher than about 13 amps, you can add a hard start capacitor like this Supco SPP4E.

[Parisjet]

• Capacitor is a 50+15 uf. The old one tested 49.6+15uf my first thought was it is the capacitor.
  
• I put a new capacitor in anyway, AC works like a champ, note to self, don’t always trust a old part even if it checks out.
  
• Compressor draws 6amps initial dropping off to 3-4 amps
  

           

[Parisjet]

Jim and Richard, thanks for your quick reply’s, maybe you can help me with my compressors not coming on.

By the way, as an A&P mechanic with Inspector authorization from the FAA, I can fix darn near anything from a Turbine engine to fabric on a PIPER Cub and everything in between. I have done ground up restorations on 12 collector cars and 8 Airplanes and am a Tool alcoholic so have multiples of everything.

Now when it comes to a Newell, I am a newby and need guidance now and then. I love this site and search threads thoroughly before posting for help. Tom is very generous with his time and advice but I don’t want to be a pain.

[hypoxia]

You'll fit in fine and we'll be asking for your help before long. I did the Husky factory tour a couple of weeks ago, nice.

Are you sure you don't have a PTCR or another capacitor in there somewhere? What make/model?

It seems like the pressure transducer would be the first suspect with your compressor problem?

[johnkosir]

As a retired AC mechanic I think a unit drawing 3-4 amps is not moving much heat I would like to see 10-13 most of these units were designed to run on a 15 amp breaker and you are only allowed too draw  80% so that would be 12 amps. I am guessing you are under charged, A easy way too check would to check the temp of the suction line leaving the evaporator and the temperature of the air leaving the coil  should be  15 to 20 degree difference, another way would be too check the suction pressure, I would use a  pair of pinch off vice grips and pinch off the 1/4" line on the compressor that is pinched with the end welded shut close to the compressor cut the pipe use sulfoss or silver solder to braze on a access fitting with the schrader valve removed cool down the joint with a wet rag being careful not too get any water in side, put the shrader back in, take off my pinch off vice grips squeeze the line to open it up a bit where I pinched it off, check my joint with soapy water  for a leak, put on a set of gauges and check the pressure, my 2004 uses r410 so pressure should be over 120 psi. 1or 2 ounces of freon would make a big difference. If the unit was giving me starting problems I would not think twice about putting a hard start kit on it. 
I have 1 thermostat in the kitchen but I can set each unit too its own temperature and would be surprised if you can't .
 If you change the unit you have too find 1 that will work with that thermostat or fish wires for a new thermostat in the bed room

[Parisjet]

It has what i believe is a PTCR Capacitor rated at 47-56 mFe (see picture) it was measuring 48.5 

The draw was low today as the hangar was 62 degrees, will probably be higher on a hotter day. Will shoot the temp high and low lines. Air in coach was cold, will check with temp gauge to verify. All might be well now with the new capacitor.

I can set the temp for each of the 4 units but don’t know if Newell uses one thermostat with 4 remote sensors or not

   

[johnkosir]

each unit has its own sensor