Air conditioner stopped working

[EMD360]

It hums for awhile but does not kick on. It’s a Coleman 48000 series. 15,000btu.
Owners manual says the compressor might not kick on if the filter is dirty but it’s not. Also that there is a high pressure lockout switch. I have not gone up to check out the unit. Any hints about what to test or look for? Just clean it and see if the problem persists?

[EMD360]

Wondering what happened? Sad tale. I got an appointment at the local Camping World in Golden for a diagnostic. They found that the electronic thermostat had died. Even though it still turned on the heat. Even though I tried reinstalling the old thermostat. So the new run and fan capacitors were fine. I was going to skip the diagnostic if I had gotten it to work. But since I didn’t fix it myself it cost me $650. They also did a 10 minute inspection that was not covered by insurance. The idea was to find anything else that I could claim. Naturally nothing. And excluding the service cost I probably didn’t hit the $500 deductable.
They found the high fan was wired to the neutral! I must have miswired when I reinstalled.
But I found the new repair shop in Golden to be quite nice. The new regional manager was there getting it up to speed and training new staff. I needed the new thermostat before I left for a trip this week. When it had not arrived by Friday he sent staff to another store to pick one up. Told me to come right in and they installed it correctly. They may be expensive but that was excellent service. While I was there I observed him handling other problems and training new staff and being an excellent customer care person. It was kind of obvious the existing staff was not used to going the extra mile. I hope he is successful changing that. Camping Workd needs a better reputation.

[EMD360]

I could not figure out why the high wire doesn’t operate. There is no speed selector switch to test. The wires are plugged into the control board.

Unfortunately I think I blew the electronic compressor circuit on the expensive Bluetooth thermostat because when I hooked it back up the compressor would not stay on. I re-installed the original thermostat and it’s working. I didn’t hook up the hi fan since it sparks on application of power.
So it could be the wire or the control board I guess.
The impeller turns freely as does the fan blade but I noticed the impeller has a chip in it wher part of a fin is broken off. That seems weird.

[EMD360]

It’s the high fan wire. It’s shorted out. I tested the thermostat and got a spark on the green wire. Took off the thermostat completely and got the same spark between the hot and hi fan. All the other functions work; low fan, compressor, and heat. Apparently auto hi and auto lo do nothing. I’m not sure why they cycle through. So sounds like I need to find the short! That does not seem like it’s going to be easy. On the other hand I could just tape it off. The air works fine on low cool. I found the only difference between the lo cool and hi cool is the fan speed. I hope I didn’t fry the thermostat when the green wire sparked!

[EMD360]

Maybe. I checked that the thermostat wiring was secure but I probably need to put power directly to the hi fan wire.

[Ranger_Smith]

That sounds like a thermostat issue.

[EMD360]

I waited for the OEM run capacitor that came today. I installed it and a new fan capacitor. Now both work on low but not on high. Can’t find anything to explain that. Could the fan motor be broken?

[Ranger_Smith]

That black capacitor you have will replace the big one with the yellow wire on it. According to the parts list it is a 40 uf capacitor and your 47 to 56 will certainly work.
11. All 1499-5721 Run Capacitor (40 Mfd/370V)
12. All 1499-5461 Fan Capacitor (7.5 Mfd/370V

[EMD360]

Thanks! Hmm the parts list says it’s a run capacitor. Same thing? In some models there are three capacitors including start, run, and fan. This one only has two. I ordered the small black one before I looked in the compartment.
Turns out I can’t get a shop to look at it until July 19th. We are taking a trip to hot Indiana on July 27th.

[dougrainer]

The smaller capacitor with the brown wires is the Capacitor for the FAN. The other Capacitor is the START capacitor, the yellow wire. Get the info off the existing larger capacitor and go to a local AC supply house and get one. Also, Amazon may have them and Grainger will have them. Doug

[EMD360]

Maybe the unit needs a hard start capacitor. But I understand that is just when the generator does not have enough power. The AC does not start even on a 30 amp outlet.

The run and fan capacitors are inexpensive. I'm reading about how to test a capacitor. Should I test the incoming voltage to be sure its getting enough power?

[EMD360]

Parts List and Unit ID
Darn I found the issue. The parts list designates a start capacitor only for the 87* Series.




Parts 15,16,17.
Model Used Part Number Item
16. 87X 8333A9021 Start Capacitor Pkg. (88-108 MFD/165V)

[EMD360]

The part finally came. I didn't call insurance because it would cost at least $500 to fix and it looked so easy. Opened up the panel and I don't have a start capacitor!

Just a run and a fan capacitor?
The start capacitor that I received is listed in the parts diagram for the 48000 series but there isn't a corresponding part inside the AC.


Now what?

[JimK-NY]

A few years ago my unit would not start and I could hear a humming sound. Even the fan would not start.

I went up on the roof, removed the cover, turned the exterior fan. No more problems until this Spring when the same thing happened. The bearings are sealed and cannot be lubed. I think a build up of dirt and grime is the issue. Anyway mine still works fine as long as it is used with some frequency.

[dougrainer]

EMD360 wrote:
I’m just going to ask for an authorized shop. Then see how long it takes to get an appointment. I still think I’ll install the part because I bet it will take weeks.

Since it is an ESC, you can take it to any RV service shop. Doug