AC unit wiring question

[gordinho80]

My travel trailer build has been very slow going. 2 years ago I removed the AC unit from the roof in order to replace the roof completely. I can't seem to find the pictures I took of the wiring prior to removal... 😞

So here I am now trying to figure out what wire goes to what...

AC unit has 11 wires...

RED - TAN - YEL - WHI - BLU - ORN - BLK - GRN - RED/WHT - BLU/WHT - BLU/WHT

There are 2 thin guage wire sets that run into the trailer... One has 2 wires, RED - WHT. The other has 6, RED - YEL - WHT - BLU - TAN - GRN .

The thermostat has the same 6 wires connected to it.

Trying to figure out what wire from the AC unit goes to what on the thermostat side...







There is also 110 wiring... from the AC itself, there is your standard WHT - BLK - Ground. There is a WHT and a BRN wire that is ran through the same port as the 2 thin sets. Plus a 110v box with WHT - BLK - Ground

[gordinho80]

wnjj wrote:
Did you ever get a chance to connect it up? I’m curious if it’s working.

Just wired it up yesterday. Thanks so much! Everything working as should be... well, I assume. I haven't tried it on HEAT yet as I don't have the furnace all hooked up and no propane currently.

[wnjj]

Did you ever get a chance to connect it up? I’m curious if it’s working.

[wnjj]

OK, so I found a Dometic installation instruction that while it may not be your model, the wiring colors are the same.

https://www.manualslib.com/manual/808076/Dometic-620412-331.html?page=13#manual

For the following, I'll refer to the separate brown & white as the supply wires, the red & white pair as the furnace wires and the 6-conductor as the thermostat wires. The wire colors in all CAPS will be the 11 A/C wires.

According to the doc above:

1. Connect large the +12V brown supply wire to A/C RED (after you confirm it's the one from your fusebox).
2. Connect the large white supply wire to A/C BLACK.
3. Connect the thermostat red wire to A/C RED/WHITE (+12V out to thermostat).
4. Connect the thermostat green to A/C GREEN (gnd).
5. Connect the thermostat yellow to A/C YELLOW (cool).
6. Connect the thermostat tan to A/C TAN (fan).
7. Connect the thermostat blue to A/C BLUE (hi fan).
8. Connect the thermostat white to A/C WHITE (heat).
9. A/C ORANGE is not used (no HS/HP terminal on your thermostat).

I take back what I said previously about the furnace wires (red & white pair). It seems this A/C unit takes in the thermostat white wire and provides a set of BLUE/WHITE that short together to run the furnace. Based upon that, I'd say the 2-wire red & white furnace pair connect to the A/C BLUE/WHITE wires.

[gordinho80]

Its a Dometic, not sure the model.

[wnjj]

The 2-wire thin pair (red/white) likely comes from the furnace. Usually power comes up the red wire and is switched on/off on the white wire by the thermostat. That white wire needs to connect to the white one coming from the thermostat 'heat' pin (also white). The red wire may also need connected to the thermostat + wire (red).

Some of the wires in the 6-wire cable look like they were cut and/or never used. I assume some of those broke off when you disconnected them?

The A/C will need a wire for cool, fan, high fan, power and ground. The brown and white larger wires probably provide the 12V power for the A/C unit.

What brand is the A/C?

[gordinho80]

Wiring coming from the AC unit itself...

the 11 that I mentioned prior, the first pic in the first post shows the label of these 11 wires. Then there are 110v black, white, and ground...



Here you see the 110v wiring coming from the trailer breaker box...



ANother grouping of wires coming from trailer. The 2 sets of thin wires including the one going to thermostat.



There is also a thicker brown and white which I believe connects to the breaker box here:

[opnspaces]

In the circuit board picture are there any labels on the board above the blue 6 pin connector?

[gordinho80]

No other board. I really wish I could find the picture of the wiring before I removed the unit. Perhaps I did not take one... 😞

I'll try to get a picture of all the wires as they are.

[theoldwizard1]

Is there another circuit board ? The drawing show the wires from the thermostat going to CON1 (6 pin, rectangle) and CON2 (4 pin square).

The only brown wire I see goes from the Fan half of the Run Capacitor to the Fan. White connects to the center terminal of the Run Capacitor and many other things (it is the 120VAC neutral).