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Topic: Roof A/C electrical connections (Read 385 times) previous topic - next topic

Roof A/C electrical connections

I am having a difficult time rewiring a new Dometic a/c into the original wiring in my coach.  Can someone direct me or identify for me the wiring associated with the 12 volt side of the installation?  I'm trying to figure out how to connect the new control box with the older hard-wired control board wiring, and I would like to know which of the wires control what.
Thanks, Mike
Mike Brady
'97 U320 SE. #5137
'13 Honda Fit
Willow Springs, MO

Re: Roof A/C electrical connections

Reply #1 –
If you don't buy the wiring harness from Dometic to add to your existing wiring, you can bypass the plug and take your existing wiring straight to the control board.  I recently upgraded my boards and had to remove the new boards from their enclosures to wire them up and fit them in the older Duo Therms.  All of the existing wiring works and the board is pretty well color coded and marked at each terminal.  As you disconnect each wire from the plug in the box, reconnect your existing wire to the same terminal.  You'll also need to set the jumper pins while you're in there.

Re: Roof A/C electrical connections

Reply #2 –
The new control boxes contain the new boards, which has a six contact plug coming from the new a/c.  The new control box is wired in to the old existing wiring, and there is no corresponding color coding of the individual wires in my coach.  This is where I am having the problem.  Along with this, the old 4 button thermostat has to be replaced, which I chose a 5 button because of the same footprint as the 4. 
Mike
Mike Brady
'97 U320 SE. #5137
'13 Honda Fit
Willow Springs, MO

Re: Roof A/C electrical connections

Reply #3 –
I don't know what to tell you.  That doesn't sound like the wiring in my coach.  Yes, the new board has a 6 pin female plug that is mounted directly to the board.  That plug connected to an existing male plug.  The new board was also wired to another plug on it's enclosure that I disconnected in order to directly connect the remainder of my existing wires, which transferred 1 by 1 from the old unit.  The wire colors corresponded to positions on the board (red and yellow for fan speed, black & white to compressor and fan relays, etc.).  The board has 2 RJ12 plugs, which should be the same regardless of the the 4 or 5 button thermostat.  Those 2 plugs are not labeled for input or output but Dometic told me that it doesn't matter....plug either cord into either plug.  I've attached an installation document that has a wiring diagram on Pg 15 that might help, and another with instructions for upgrading from the 4 button to 5 button thermostat.  I can also post pictures of mine when I finish the installation this weekend.

Re: Roof A/C electrical connections

Reply #4 –
Pictures of you setup always helps.
'99 U320 40 WTFE
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