cancel
Showing results for 
Search instead for 
Did you mean: 

Rooftop ac repair

mike_brez
Explorer
Explorer
Ok both my rooftops are not working. Dometic Duro Therms.
Took covers off and installed peircing service valves. Both had no freon. Both had pin holes in capillary tube in same place apparently rubbing issue. Cut sheet metal to access. Put a drop of braze on one and cut one out and sleeved with a peice of 1/4 inch tube and brazed. Pulled a vacuum on both and filled both with 24.5 oz of r22.
Wasn't very warm but shot the rear plastic ac grate with ir gun 67* fired up generator turned rest ac an feels cool 15 min shot plastic ac grate again in same spot 48*
Shut down rear and started front. Fan comes on but compressor keeps on trying to start every minute or so and cuts out. Removed wires from compressor and all have continuity. Switched all capacitors and compressor over load switch from working rear to front and no change. I guess compressor is locked up. Was thinking of trying a hard start kit but not sure it would work. Was thinking about trying to find a compressor but a quick search showed nothing. Gotta hop back on roof and get numbers off it. Here's a few pics.







1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU
33 REPLIES 33

mike_brez
Explorer
Explorer
Branson N Tucson wrote:
By your profile your MH is a 1998.
If they orginal units, you may consider replacing them. You sound very mechanical incline and could install them your self. There are some pretty low prices out there, I'm sure a compressor isn't cheap.


Yes thanks ordered and allready installed two new ac units and thermostat.
Looks like I will be uninstalling them:S
1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU

mike_brez
Explorer
Explorer
Thanks guys. Should have flipped the old ones over an would have seen.
Now is it ok to flip these new ac's upside down to install the cups?
1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU

oldave
Explorer
Explorer
Mike , assuming you still have the old units .
Go flip one over and you will see the little pans .
If they are ok just take them off go up on the roof and install
on the new A/Cs .
However it wont hurt a thing to leave as is and install later
the water will just run on the roof . .

The water drips into those pans then a hose goes inside the coach
there it ties into your drain system .
You are supposed to use 2 gaskets and cut a notch between
the 2 for that hose to pass through going inside , caulk it good .
The idea is the pans catch the water , carry it back inside then down
the drain hoses .
However if the drains get stopped up then the pans just overflow out
onto the roof instead of in the floor .
Pretty neat .

Branson_N_Tucso
Explorer II
Explorer II
By your profile your MH is a 1998.
If they orginal units, you may consider replacing them. You sound very mechanical incline and could install them your self. There are some pretty low prices out there, I'm sure a compressor isn't cheap.

dougrainer
Nomad
Nomad
I would purchase 2 new drain cup kits from Dometic. After all these years the Plastic will be very brittle and will probably crack. That is what I would do if I was doing this for myself or a customer. Doug

https://www.vintagetrailersupply.com/Dometic-Air-Conditioner-Drain-Kit-p/vts-079.htm

mike_brez
Explorer
Explorer
Thanks Dave. I didn't see any installation instructions but I'm guessing sence I allready installed the units I need to unbolt them from roof to install them.
1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU

oldave
Explorer
Explorer
mike brez wrote:
Hey Doug my coach has a hose for each of the ac's so the water drips on the ground near my front tire and rear bumper instead of running off the roof.
Is their a way to do that with these ac's?


Not Doug but I think I can help .
That part of the units is an added part . It is 2 little plastic pans
that attach to the underside on the outside of the unit
They are held on by 2 screws and can be moved from the old A/C
I was concerned the plastic pans were old and fragile so I ordered
new ones . This is the kit, if it was me I would order 2 kits

https://www.ebay.com/itm/Dometic-3107688-016-Drain-Kit-System/292993702423?epid=1023679643&hash=item4437c91a17:g:AZUAAOSwrYRciatG

mike_brez
Explorer
Explorer
Hey Doug my coach has a hose for each of the ac's so the water drips on the ground near my front tire and rear bumper instead of running off the roof.
Is their a way to do that with these ac's?
1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU

mike_brez
Explorer
Explorer
oldave wrote:
Mike , Did you order a new thermostat too ? I'm pretty sure your old
one will not cooperate with the new units . The new thermostat is plug
and play same as the old one .

Your old thermostat may be worth more to someone than the old A/C units .

Measure the spacing of the 4 long bolts . Mine was slightly different
by just a small amount and I didn't know it , caused me a little grief.
I had to enlarge the holes where the bolts pass through a little .
Good luck


Thanks for the tip. I did get a new thermostate also.
1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU

oldave
Explorer
Explorer
Mike , Did you order a new thermostat too ? I'm pretty sure your old
one will not cooperate with the new units . The new thermostat is plug
and play same as the old one .

Your old thermostat may be worth more to someone than the old A/C units .

Measure the spacing of the 4 long bolts . Mine was slightly different
by just a small amount and I didn't know it , caused me a little grief.
I had to enlarge the holes a little where the bolts pass through
Good luck

mike_brez
Explorer
Explorer
Ordered two new Penguin 15k with heat pumps yesterday. Rear ac is working good but want both to be the same. If anyone in ct area can use a ac or some parts it's yours.
1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU

rgatijnet1
Explorer III
Explorer III
Did you see what the voltage dropped to when the AC unit tried to start? Perhaps the voltage is dropping below that required to start the compressor. Just a thought.

mike_brez
Explorer
Explorer
Ok I'm done. Tried to beat on it with a rubber mallet while it was trying to start..nothing.
Went to the ac supply house and picked up a hard start kit...nothing.
1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU

dougrainer
Nomad
Nomad
oldave wrote:
Mike
If you have ducted air conditioners now and replace them with the same
I don't see why any thing inside like grates or grills would need changing .

Ray


Depending on HOW the upper unit is connected to the duct system, may require modification on the hole in the roof on the topside. Usually, only Newmar Motorhomes have this problem from the OLD Penguin to new Penguin. Doug