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folivier
06-19-2009, 01:15 PM
My front A/C quit cooling yesterday. It had tripped the breaker and L1 light was out. I reset breaker and L1 light came back on but a/c is not cooling. Also a small refrigerator quit cooling about the same time but it is on a different circuit (light was on but not cold) don't know if they are related. (I'll probably either replace the refrig. with a freezer or built a set of pantry cabinets.)
I plan to check the voltages on the a/c first to make sure they are good. Then I'll clean both coils, if that doesn't work I'll call my house a/c guy and see if he can check it out. Hopefully it's not a bad compressor, I understand these Dometic basement units are obsolete?
Any other things to check out? What other options besides installing a roof A/C?
Thanks.

tuga
06-19-2009, 01:32 PM
Forest,

I had a 1993 Newell with basement ACs. On mine, the problem was the condensor fan motors. They would burn up; I had to change 5 of them during the 9 years I had the coach. Newell could get them for me from a supplier they had.

The problem with the fan motors was they could not be oiled so after a few years they would burn up (at least that's what I was told). Like most other problems there was no logic: the front AC and the middle AC would burn fan motors - the bedroom never had any problems in 9 years! If I remember the little fan motors were about $250 and would last a couple of years. If Newell can find one for you, I would order a couple of spares. The hardest part about changing them is removing the squirrell cage from the motor shaft. Cleaning the evaporator and condensor coils always helps. Be careful not to bend the fins with too much water pressure.

Hope this helps.

P.S. I am still planning to come by and see your coach (just been busy). I'll call you soon.

zcasa
06-19-2009, 02:56 PM
Forest, I have the same experience as Tuga. I have three basement units and the front one has gone through two motors in four years of ownership. The other two units have not had any issues. My front one would trip the breaker. Once a new motor was installed, everything worked very good for two years and then it needed a new motor again. Go figure. This must be a regular occurrance, as Tuga states, because when I purchased the coach four years ago, four spare motors came with it. Now I'm down to two.

Have a good day.

David

chockwald
06-19-2009, 03:05 PM
Love those roof A/C units...they just take a "licking", but keep on "ticking"....oh, wait a minute, that's the Timex motto....LOL! Seriously, though, I hear this a lot about the basement A/C units. Have never had this kind of an issue with the roof A/C units on my Newell, or on the Class C I had before. In fact, the A/C units on my Newell are the originals, and they still blow ice cubes.

fulltiming
06-19-2009, 03:18 PM
The only problem I have had with my basement AC's (other than a strange thermostat wiring issue with one that was preventing it from coming on at all) was loss of refrigerant. As we live in our coach, the AC's run ALOT!! I suspect that since the breaker trips, you have either a fan motor or the compressor motor failing. Try resetting the breaker, then check the voltage on L-1. Assuming it is 112 or higher, turn on just the fan for the AC that quit working. If the interior fan comes on, you know the problem is either the evaporator or the fan in the basement OR a short in the wiring. Turn on the other AC units so you can determine which one is the unit that you need to access. In many of the pre-1997 coaches, two AC units were stacked on top of each other in the front driver's side bay. If it is one of them, you can remove the retainer panels around the outside of the grills after opening the access door, then slide the units out as they are typically on a metal slide. Check the wiring to see if a critter has been snacking on the wiring (I do have a dead mouse inside the wire screen on one of my front two units but no wiring damage). See if the fan motor turns fairly freely. If not you fan motor is shot. If the wiring looks OK and the fan turns easily, disconnect the fan motor but leave the compressor still wired into the power. Turn the problem AC unit to cool and turn the thermostat down so it will come on after the couple of minute delay. If the compressor starts without tripping the breaker, you have isolated the issue to the fan. Although it is not easy to find parts to the Dometic basement AC's used in these coaches, folks have found sources during the past couple of years for the fan motors and for the compressors.

folivier
06-19-2009, 05:45 PM
OK, cleaned the outside coil & let it dry; the inside fan runs ok, outside fan runs ok, compressor runs - body gets hot. But the unit does not get cold, the cold copper line does not get cold.
Maybe it's just low on freon?
What type of freon do these use?
Guess I'll call my A/C guy next. (He installed a new unit in the house last week, why didn't this happen last week?)

Richard and Rhonda
06-19-2009, 09:52 PM
Forrest,

You said the compressor runs. Have you clamped an ammeter around the compressor wiring to see what it is pulling?

The gas in mine is r-22

I had a different problem with one of mine. The circuit board that controls the unit has a relay on the board that turns the compressor on and off. That relay burned up. Although, I could not source the board from Dometic, I was able to easily obtain a exact replacement for about 20 bucks. The boards are contained in a small silver box located close by the evaporator unit in the coach.

folivier
07-01-2009, 09:16 PM
A/c guy just left. He found that a wire had shorted out to the tubing and arced a hole in the tubing. Soldered, evacuated, filled and works great!
That's what tripped the breaker. When I was checking it out after it quit cooling I noticed one wire had the insulation worn off and the wires were very long and just hanging, so I shortened all of the wires going to the blower fan. If I had looked longer & with a flashlight I would have seen the hole in the tubing.