Duo Therm A/C problem

[Bill Stireman]

Anyone have an idea what is wrong here?  Our front A/C quit last night.  There is no power to the thermostat.  The rear A/C quit at the same time.  There is power to the rear thermostat and it will run on fan only and will control my Aqua Hot in that zone.  I switched out the thermostats to see if it was a bad thermostat and the front one works the same way as the rear one when hooked up in the rear.  Of course I have checked breakers and fuses and they are fine.  We checked the three amp fuses on the roof units and they are fine.  Any suggestions?   Would like to get this fixed asap so we can get the Aqua Hot working in the front of the coach as it is quite cold down here in the Keys right now.

Bill Stireman
'04 Monterey
at Sunshine Key RV Resort

[Richard And Babs Ames]

Did you check for power to the front thermostat? The LCD would show if it has power.

[Bill Stireman]

there is no power to the front thermometer

[Edward Buker]

Consider running a small wire with a 2 to 5amp fuse holder built in up to the dash and pick up a temporary 12V feed. You can route it on the floor and behind furniture as a temporary path. It may get you back online for now and will let you know that just the power feed is involved and if that was repaired the thermostats and systems themselves are O.K.

Here are some service info links that may help.

http://bryantrv.com/docs2/docs/acservice.pdf
http://www.cleggind.com/postal_tech/pdfs/AC1/3108373%5B1%5D.022.pdf

later Ed

[Bill Stireman]

Thanks Ed, I'll give that a try.  Don't know why my previous reply was posted twice.

[Richard And Babs Ames]

The power comes from the AC to the thermostat. I would make sure all the thermostat wires are connected at the AC before trying anything else.

[Paul Bowers]

I had a similar problem not too long ago.  My GFI had popped and cut the power to my A/C.  I reset it and no problem since.  Felt it was just a power surge that got it the first time.  Might be worth a try...even if they haven't popped to test and then reset.

pb

[Edward Buker]

Richard and Paul bring up good points. I have not had problems with my unit and have not studied the thermostat voltage source. I glanced at a wiring diagram and 12v appears to be fed from the air conditioner to the thermostat. 12V is fed from the coach wiring harness to the rooftop airs. You should see if the roof airs are getting the 12V supply and if not see where that originates from. If 12V was brought separately to the thermostat, it may backfeed to the roof air through the existing wiring harness and that may get you running temporarily but I'm not sure. It would depend on how the system is designed.
Hope this helps and you are warm tonight...
 
later Ed

[Bill Stireman]

Problem solved.  It was a corroded connector on the 12 volt feed in the bay with all of the wiring.  Put on a new connector and solved the problem.  Thanks for all of the suggestions.

[Edward Buker]

Bill,

Glad you are back online and that the fix was simple...maybe not so simple to find though.

In the prevention category this product is very good. It is clear and clean and used in the marine industry to coat connectors and terminals to prevent corrosion. It is not for terminals under the chassis exposed to salt, you need something that coats and cures there, but for areas like the electrical bay under the drivers seat it is perfect. I spray all of the connectors in the wire bay once a year with a light coat. I use this product on a Honda Outboard that sees salt water use. I was told by the dealer to remove the motor cover and spray the engine exterior after use and flush. It has literally eliminated corrosion that had started before I used this product. This may help your issue...

http://www.amazon.com/Corrosionx-16Oz-Aerosol-Corrosion-X/dp/B0009E1QWI/ref=sr_1_5?ie=UTF8&qid=1292422483&sr=8-5

Later Ed

[Bill Stireman]

Ed,  Thanks for the tip.  I have been using CorrosionX for quite some time.  My only complaint with it is the price.

Bill

[Edward Buker]

Bill,
It is a pricey product...probably a lot of profit in it but a can does seem to last.

Out of curiosity, I think the wire connection was in the electrical bay, had that gotten wet somehow?

Enjoy the keys, should be getting warmer now.. 60 up by Pensacola this morning..
Later Ed

[Bill Stireman]

Hi Ed, no the bay did not get wet and the connector was only slightly green inside, so I think just normal airborne moisture did the trick.  Beautiful day here at Big Pine Key. 72, sunny and no wind.  More good stuff on the way.  Life is beautiful.

Bill