Originally Posted by Drusser
We have a basement 6535B871 Cloeman-Mach unit (a/c,heatpump) on a 2006 Winnebago Adventurer 38T. It is blowing cold air but only in the 1st phase, the 2nd compressor doesn't kick in. Any clue as to what might be causing this issue? Thank you.
First, you do know that for both compressors to run the ambient temp and the thermostat temp must be at least 3 degrees apart?
You are sure the second compressor is not working? Test by turning off the breaker for #2 compressor. Then start the AC. give it a minute and then turn the breaker on. You should be able to hear it start. Don't know where your breaker panel is but on my Journey it is under the foot of the bed. Velcro panel that pulls off covering it.
If you can't hear it, disconnect from shore power, start your generator, start ac #1 and read the amps on the load panel. Start AC #2 and see if it changes. If draw goes up but it does not appear to start you could have several problems. If load does not go up here is where I would start.
Take the cover off your distribution panel, check for voltage at the bottom of the circuit breaker. No voltage, pull the breaker out and test it with the VOM. If it is good it should have close to 0 ohms when on, trip it and should go to infinity.
If you have voltage At the breaker, go to the outside panel covering the AC unit. There are 2-4 screws on the bottom of that panel, both front and rear. Then that panel swings up just like a compartment door. Prop it up so you can work on it. WITH THE POWER TURNED OFF both shore power and generator power there will be a cover with 4-6 screws in it toward the rear of the unit. Take it off. Discharge the capacitors by using a screw driver to touch the housing of the capacitor with EACH of the terminals on top. You may have already found the problem if one of the start capacitors is burnt, or the wires to it are. There are 2 black start capacitors that have a little gismo on the top. These start capacitors are the most likely to fail. There are also 2 silver run capacitors. Again, make sure you discharge them before touching any of the wires. They can give out quite a shock. Test the capacitors. I won't go into how but if you google how to test a capacitor you'll find instructions. I have to look them up every time I do that. They are easy to change and relatively inexpensive. Just take a picture so you know where all the wires go on the new ones.
The other thing you can do, CAREFULLY, turn shore power back on, thermostat off, both ac breakers on, you will see on the lower left where the ac line lines come in. Check both to make sure you have 120 volts.
If all this checks out, with the covers still open, turn the 1st ac on, then the second. It's hard if the 1st is running to hear, but you may be able to hear the compressor try to start.
At this point it is time to turn to a pro. If you have voltage to both lines to the unit, have checked the capacitors and they all look ok and test ok, you could need a control board, relays or a compressor. Hope for a control board. $248. Don't ask me how I know. I watched a guy do one and with all the wires it looked like he was eating spaghetti.
If it is a compressor, and guys who know what they are doing in these things know how to jump the compressor (it just runs off 120v) they can jump just one and hear if it runs. This is all stuff I do not try myself, and I'm pretty good with electrical (but not electronics)
If in fact it is a compressor, if you feel up to it, you can take the unit out yourself. A bolt on each corner. After disconecting the wiring, and all you really need to disconnect is the 120 in and the plug for the thermostat that is right in the middle, 9 wires, one plug. Get a jack and some boards, take the 4 bolts out and lower it down. Goes down mabey 6-8 inches and then you just pull it out. Keep in mind they weigh about 250#.
From that point, either an RV shop if you have them do it, or yourself, will take it to an HVAC company to replace the compressor. They are a closed unit and require cutting lines, soldering in valves, evacuating and recharging. Then they can bench test it.
You can buy brand new units for around $2200, but from what I've heard, they are not exactly the same size and venting and take some major remodeling of the ductwork and mounts to replace. My trusted RV shop just did one, and said it was cheaper to fix than to remodel to make a new one work.