Dometic Duo-Therm 13500 roof top AC not cooling

[ckmj]

1999 Georgie Boy Cruise Master 3515 50amp service

Dometic Duo-Therm 13500 roof top AC single zone analogue

(no heat strip)

Model number: 57915.622
Start Capacitor: 3310727.007
Control box: 3107541.009
Relay Circuit Board: 3106996.022


Good evening

Hopefully an RV AC tech will see this.

I have a Dometic Duo-Therm roof top single zone ac unit. Two
days ago it stopped blowing cold air.

We heard a clicking off and on over the last month, after it
went out, I did some testing.

First thing I did was swap out the living room thermostat
with the bedroom to rule that out too. Both thermostats are
good.

Being inexperienced, I wend out and bought a start capacitor
and installed it on top. (Start Capacitor: 3310727.007)Powered up and nothing. High fan and Lo fan both work. Just no compressor.

I found this thread here in RV.net:

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/23798899.cfm

The pictures in that link are accurate.

I read the thread and pulled the over off the control box to
get to the circuit board, fuse was good, and the thread said to jump the black and blue wires going to the relay, I did with a screwdriver and the compressor started.So from what I read the board was bad.

I wend and bought the circuit board for my unit (Relay Circuit Board 3106996.022) and installed it, no issues.

I put it back together, powered up and still no compressor.I am afraid to try jumping it again with the new replacement board it did spark with the original board but the compressor started.

Because the fans are working, I did not replace the run capacitor.

Our campground tested our pedestal today all was OK,it was worn so they just replaced the receptacle and the 50 amp breaker anyway.

It is the back ac unit not working, I am very handy but at a loss. We are in Florida and it stinks.

My family and I would greatly appreciate some insight.

Thank you Kindly,

Charles

[forumcoach]

Test your compressor.
A few different tests.
Place a clamp on ampmeter on the blue wire running to the compressor. Watch the meter when somebody turns it on to see how many amps it is running at attempted start up.
Remove the cover on the top of the compressor, one nut holds it on. Remove the three wires. Scratch the compressor with one lead to get contact to the case. Place the other lead on a top terminal. Should be OL. If there is continuity to the case it is bad.
Measure ohms across each pair of terminals. The sum of two measurements should equal the third.
Some units have a replacable sensor on top, others are built in. Rarely fails if it has one, but you can test it.

[ckmj]

Hi,

Trying to avoid that. There are some knowledgeable people here. I am handy and that would be a last resort.

Just something I am missing.

Thank you.

[midnightsadie]

maybe a mobil tech in the area.