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Randall
Randall, RVIA Certification
Category: RV
Satisfied Customers: 10747
Experience:  RVDA/RVIA Master Certified Technician with many years experience.
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I needed to replace my old Duo-Therm RV unit with a new

Customer Question

I needed to replace my old Duo-Therm RV unit with a new Dometic B59516.711JO. How do I rewire the new Dometic Digital Single Zone LCD Thermostat with the 10 wires from the old analog unit?
Submitted: 1 year ago.
Category: RV
Expert:  Michael Reush replied 1 year ago.

Hi, I have an excellent document describing this, please review it, and get back to me for clarification thanks Michael

Customer: replied 1 year ago.
I have a (10) conductor cable from the old Duo-Therm unit. One wire I do not have is a red/white combo. Just a separate red and a separate white. Also what do I do with the old Purple, White and Grey wires which make up the (10) conductor cable? My single zone LCD thermostat is actually model #3313192.
Expert:  Michael Reush replied 1 year ago.

thanks, ***** ***** new thermostat only uses 3 wires, disregard the wires original purpose...........determine which 3 wires you want to use, and designate one for positive.......one for negative..........and one as the communication wire

Customer: replied 1 year ago.
I have tried 3 wires. I have power going into the switch but nothing from the switch. Suggestions?
Expert:  Michael Reush replied 1 year ago.

so at the thermostat do you have 12volts positive, 12volts negative, and the third wire (which is the communication wire ) attatched, and at the air conditioner do you have the 12volt to the control, and also to the thermostat? and comm wire atatched? does the display light up on the thermostat?

Customer: replied 1 year ago.
The display does not light up. Do you have a suggested wiring diagram with the (10) conductor wire?
Expert:  Michael Reush replied 1 year ago.

did you receive a new control unit and thermostat?

Customer: replied 1 year ago.
the power was tested from the control unit not the thermostat as I previously stated.
Customer: replied 1 year ago.
There is a 6 volt plug on the board. What should I plug into that?
Expert:  Michael Reush replied 1 year ago.

Hi what is the part number on the control box? thanks

Customer: replied 1 year ago.
Thank-you for your time. We are getting nowhere
Expert:  Michael Reush replied 1 year ago.

I will opt out and allow another expert to help you.........the 2 pin connector is not used, thanks

Expert:  Randall replied 1 year ago.

What Michael gave you is correct..........some parts of the new box you won't use. Did the old thermostat have the leads from the furnace coming into the thermostat at that location or at the A/C location? Those would usually be the red and white bell wires. The new wiring depends on where those terminate. You may need 4 of the 10 wires instead of just 3. Get back to me and I can direct you further. A phone chat may be useful here. R.J.

Customer: replied 1 year ago.
Thank-you for your response. I am not at the RV (90 mins away) so I will try again. All 10 leads were into a plug that plugged into the old analog thermostat.
Expert:  Randall replied 1 year ago.

Yes...........and now you won't use most of those. The new thermostat only uses 3 wires (most of the time) but that depends on how the furnace is wired up. As you know, the old thermostat controlled BOTH the furnace AND the A/C. The new one will as well. What I need from you is IF the old thermostat got the furnace leads from up above at the A/C (which I suspect) or did those leads come into the thermostat from the wall AT the thermostat. That will determine how this is wired up. There will be "extra" wires that won't be used AND a plug on the new control box that won't be used as well. So give me the layout you have and we can sort this out. R.J.

Customer: replied 1 year ago.
Thank-you for the reply. All leads are from the A/C but come from the wall. The 10 lead wires are orange, gray, green, brown, blue, yellow, black, white, red and purple. The RV is a 2006 model. Is there an issue with 12 volts? Also the RV is stationary and is not used on the road.
Expert:  Randall replied 1 year ago.

On the old control module, there would be a power IN lead. That should be marked as such with a "+" tag on it. Usually red/w white stripe. Do you have that?

Customer: replied 1 year ago.
Randall,I am sorry but I am not at the RV. It will take me around two hours to get there. How long will you be available today?
Expert:  Randall replied 1 year ago.

All day...........but, I am working at my shop and may not get back to your right away. This would be easier over the phone.

Customer: replied 1 year ago.
I will take off from work and go down to the RV. I am in the Eastern Time Zone. Are you also?
Expert:  Randall replied 1 year ago.

Pacific Time Zone............

Customer: replied 1 year ago.
At RV. The old control is in the Duo-Therm unit which has been replaced with a Brisk II unit. I am trying to wire the Brisk II unit to a(###) ###-####Single LCD Thermostat. The control is part(###) ###-#### The control has power. The issue is what wires from the old 10 wires to hook up the J2 plug. At the thermostat the black wire is to 12V-, Red to COMMS and White to 12V+
Expert:  Randall replied 1 year ago.

I am at lunch and when I get back to the shop I can grab one and give that too you. I plug with just two leads isn't used. The furnace leads are going to be used by the old furnace leads with a new female spade connector attached. Those should be the red and white bell wires. There were previously attached to the two blue wires coming out of the old control. Do you see those?

Expert:  Randall replied 1 year ago.

As far as colors you use goes.......white is a negative color. Red is a positive color. Use the orange for the common.

Expert:  Randall replied 1 year ago.

I should have gotten one out of the box to refresh my memory! The two lug plug is for the freeze control which has the yellow tag on it and a blue plug. The four lead plug has the red lead positive input lead, the black negative lead which goes to the negative post on the new thermostat, the orange lead which can be orange and goes to the common terminal on the thermostat and the red/w white stripe that is the positive lead TO the new thermostat. You can pick any colors out of your old harness you want, but sticking to red, orange and black would be easier to remember. What may be somewhat confusing is the old control had a power IN lead that was red w/white stripe (most of the time). Hook these up and then program it as per the instructions. Hopefully that will get you going. Get back to me if you need more as all follow ups are included in our fee. R.J.

Customer: replied 1 year ago.
Still no power to the thermostat. +12Volt to t-stat is connected to the red wire to thermostat. -12Volt from supply to t-stat is connected to the white wire to thermostat. And orange wire from plug is connected to orange wire to thermostat. This is one wire left from the plug that is not connected. The tag says +12Volt from supply. What should be connected to this?
Customer: replied 1 year ago.
Should I connect the +12V From Supply wire also to the +12V to T-stat that is connected to the red wire to the thermostat?
Expert:  Randall replied 1 year ago.

That wire goes to the positive feed that came into the old control module. It is usually red with the white stripe on the box.........did you mark those? And you should have just one open lead in the A/C now and that should be it. And second question.........yes........they all hook together, so there will be THREE wires at that junction. The one from the thermostat, the one from the control box and the hot lead we were just discussing.

Customer: replied 1 year ago.
Sorry we are beating a dead horse. The thermostat still does not have power. The junction with red/white (+12V to t-stat), +12V from supply and red wire to thermostat plus -12V from supply to t-stat black wire to white wire to thermostat does not read only power.
Customer: replied 1 year ago.
Do I need to route a dedicated 12V supply wire to the thermostat? How do I do that?
Customer: replied 1 year ago.
The A/C unit is plugged into the control box and has power. The issue is on the other side of the control box...the thermostat. That is why my last question was about a 12V supply source for the thermostat.
Expert:  Randall replied 1 year ago.

One of the three wires (red) goes to the red w/white stripe on the control box AND to the positive terminal on the thermostat. The 12 VDC power source is the SAME as it was before. That lead should be available as nothing would be hooked up to it like before. I think you should call me............

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