RV AC

The last time we camped the air conditioner would not start. It moaned a bit but didn’t kick in. A complication to the air conditioner breakdown is that I bought repair insurance for the first year of ownership because I did not inspect the RV at all when I bought it. I didn’t even test drive it. I just looked in the cabinets and overhead area and checked for obvious water leaks or delamination and said I’ll buy it. An extra $700 plus $500 deductible seemed like a good idea.

The major cost the first year was a rear brake job but it was maintenance and not covered by the policy. I was not annoyed because that made sense to me. The caveat of the policy is that work on it has to be done by pros. And maintenance records must be kept. That meant that all of my electrical upgrades and solar were no longer covered. I did the work, I could fix it if something broke.

The problem with professional repair of the air conditioner was that every shop in our area was booked solid all summer. Also there are a couple of things I could try for way less than the $500 deductible. I was advised on rv.net to replace the “start” capacitor. Some Coleman Mach air conditioners have three capacitors, run, fan, and start. But when I opened ours, I found only a run and fan capacitor.

Only two capacitors
Only two capacitors

I replaced both and the fan ran on low and the compressor ran the AC at that fan speed. But the high speed fan didn’t run and neither did the compressor on high fan. I tried to figure out that issue thinking that in Indiana we may need high level air conditioning.

I removed the thermostat and tested the wiring from the equipment. When I applied power to the high fan speed wire it sparked instead of turning on like the others. It seemed that connection had a fault. I could not tell whether the fault was in the wire or at the control board. But after all this experimentation I re-installed the thermostat and the compressor no longer ran on either low or high.

At first I could not find the correct model of Coleman air conditioner on the Airxcel website. I was not using the search function well. My model is a Mach 15 but there are multiple types of the Mach 15 model. Once I found the correct information I had to determine what applied to this model.

Coleman Mach 15 Model Information
Coleman Mach 15 Model Information

I tried ordering a fan selector switch listed in the parts information, although I didn’t know what it looked like or where it was located. I had read a tip about restoring fan levels with this part.

Coleman AC parts diagram
Coleman AC parts diagram

I figured if I actually had the part I could find where it was located in the AC. Of course the fan selector switch is for an older model so there was no location for it. Instead the fan is connected directly to the control board.

No selector switch direct wired
No selector switch, it’s direct wired

I thought that the digital thermostat may have been compromised so I removed it and wired in the old analog thermostat but the result was the same. Now I am waiting for a new run capacitor.

I also found out that the air compressor is one speed only. Just the fan has two speeds. So running the air conditioner on just low fan speed probably works about as well as high. Also the impeller on our unit has a crack in one of the blades but it does turn freely and the fan motor seems to be OK.

Fan impeller chipped
Fan impeller chipped

I have a diagnostic appointment on July 19th. I started calling in May! This date is before we leave for our next trip but if they can’t get to the job, hopefully another new run capacitor will fix the issue for our trip. I won’t wire the high fan because the surge from the sparking wire may have broken the new run capacitor. If repair facilities are not available for months the repair insurance is probably not worth the cost. I’ve been reasonably successful repairing the equipment myself.

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