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RVing message boards => Trailers & Fifthwheels => Topic started by: tprolland on October 01, 2017, 04:32:13 PM

Title: a/c problem
Post by: tprolland on October 01, 2017, 04:32:13 PM
So I'm getting our trailer ready for some trips. The a/c has problems. I turned it on and all I got was a humming. I turned it off, went on the roof and took off the a/c top  and all looked normal. So I turned the a/c on again and and got the humming again so I gave the fan shaft a little turn and it started and it seemed to run normal. Left it run for a while and the 20 amp breaker tripped. I should add the blower fan acted the same way when just the fan was running. Could this be a capacitor problem? There are two capacitors, a smaller black one (red and white wire) and a larger shiney one (3 posts: 1 orange 2 red and 3 white wires).
Title: Re: a/c problem
Post by: Boonieman on October 01, 2017, 05:50:35 PM
There are so many different configurations itís had to diagnose on here. But since you have two capacitors, one is probably for the condenser fan, the other for the compressor. It sounds like the fan capacitor is bad. Sometimes they will have obvious indications, like swelling, or a tar like material leaking out, but not always. Itís one of the cheapest replacements you can make for troubleshooting these systems. Just trace the wires from the fan to the capacitor to see which one it is if you donít have a wiring schematic available. They are easy to change out if you are familiar with electrical componenents. If you arenít, it might be best left to professionals, at a lot more cost of course.
Title: Re: a/c problem
Post by: tprolland on October 01, 2017, 08:55:13 PM
Thanks I will try this in the AM.
Title: Re: a/c problem
Post by: John From Detroit on October 02, 2017, 07:38:30 AM
Multiple issues.

THe failure of the blower to start sounds like the Start Capicitor.. easily replaced, this is a metal (usually) can around 1" diamater may be round or oval and about 4 inches long .. it will have either 2 or 4 wires to it.   (The 4 wire one is a dual cap two for the compressor).

THe breaker tripping after a few minutes running.. Have you cleaned the condener coils?  THey get clogged up and when that happens on miner...... I clean the condender.  (Those are the outside coils)

Way easier to do now that I replaced one Carrier Air V with a Coleman and the fan on the Acvent Air that replaced the other carrier with the fan from a Coleman..

Coleman's suck so all I have to do is remove the OUTER cover and clean the coils off

THe old days I had to remove the INNER cover on the condender anfd udually the fan as well to get the job done.
Title: Re: a/c problem
Post by: tprolland on October 02, 2017, 12:23:38 PM
My ac had a dual run cap and it was as dead as a door nail. It was easy to test, but a little harder to find locally. Ended up at North Trail RV and they carried a newer version of what I needed. It is up and running as I write. Thanks for the help.
Title: Re: a/c problem
Post by: AStravelers on October 02, 2017, 03:32:30 PM
Turn off the C/B to the a/c, go up on the roof and try to spin the fan with your fingers.  It should spin freely.  If not, chances are the bearings are gummed up.  You can try to spray some WD-40 and see if that will help.

My a/c did the humming and fan not turning bit about 1.5 years ago.  I sprayed the shaft were it goes into the bearings and it would work for a day or two and then quit.  I took the p/n off of the fan motor and searched the internet.  Found it on Amazon and replaced the motor.  Works fine. 

BTW the motor has a shaft coming out both ends.  One end for the condenser fan and one end for the blower for inside the RV. 
Title: Re: a/c problem
Post by: Boonieman on October 02, 2017, 04:45:39 PM
Great you got it going, and thanks for letting folks know what it was. The info might help someone else in the future.