# New Digital Thermostat



## wv outbacker

I am installing a new Coleman Mach hoc thermostat model 8330-336 in my 2013 250rs but I ran into a problem. The wires coming off of the trailer are red, red/black, green, blue, white, and yellow. The wires on the thermostat are green, blue, red, yellow, white, and grey. I know to match color for color, I just don't know what to do with the red/black from the trailer and the grey from the thermostat. Any help out there?


----------



## wv outbacker

robertized said:


> I am installing a new Coleman Mach hoc thermostat model 8330-336 in my 2013 250rs but I ran into a problem. The wires coming off of the trailer are red, red/black, green, blue, white, and yellow. The wires on the thermostat are green, blue, red, yellow, white, and grey. I know to match color for color, I just don't know what to do with the red/black from the trailer and the grey from the thermostat. Any help out there?


Here is some good information on the Coleman Mach 8330-336. Look at the wiring diagram on the last page. 

http://www.rvcomfort..._thermostat.pdf

Your Wiring

Travel Trailer Thermostat

Red  +12VDC  Red
Thank you!!!
Green Fan Hi Green

Blue -12VDC Blue

White Furnace White

Yellow Compressor Yellow 

Fan Lo Grey

Red/Black ?

Could the Red/Black be the Fan Lo wire? On our trailer the wiring coming out of the wall had the correct color wires attached to the trailer wiring. When I removed the original thermostat to install a new digital one, I made sure to leave enough of the correct wire colors connected to the existing wiring to make reinstallation simpler. You will have to use a multi meter to check out your wiring. Good Luck
[/quote]


----------



## wv outbacker

robertized said:


> The Coleman RV thermostat uses 12VDC to operate, so the first thing in tracing out the wiring would be to identify these wires (+12v and -12v). The grey, green, and yellow wires are for the AC unit on the roof and they go to a control board located up inside the return air compartment, so they operate control relays that handle the heavy current load of the compressor and the blower fan Hi/Lo speeds. The white wire goes to the Furnace control panel to operate it. The thermostat is a low voltage/low current control device that sends +12vdc to the individual control boards to operate the selected functions. What I have used to mark wires in the past is to use a two inch or longer piece of masking tape that I fold it over each wire so I can write on the tape to identify the conductor. Once you have identified the +12vdc and -12vdc conductors you should be able to use the +12vdc wire as a hot lead to momentarily touch, one at a time each of the remaining wires to see what function they operate. If you are not comfortable with doing this, then it would be best to get some local help. Good Luck.


Thank you so much for your help. I have a feeling the black and the red/black wires are the +12v and -12v because they are thicker wires than the red,yellow, white and blue wires. I will let you know how it works out.


----------



## CaptFX4

I ordered this same thermostat and should be here any day. Let me know what happens.

Pictures if you got them.

Thanks.


----------



## wv outbacker

CaptFX4 said:


> I ordered this same thermostat and should be here any day. Let me know what happens.
> 
> Pictures if you got them.
> 
> Thanks.


Will do, probably won't get to it until the weekend.


----------



## wv outbacker

CaptFX4 said:


> I ordered this same thermostat and should be here any day. Let me know what happens.
> 
> Pictures if you got them.
> 
> Thanks.


Did you hook up your thermostat yet? I haven't and wondered how you did yours?


----------



## CaptFX4

wv outbacker said:


> I ordered this same thermostat and should be here any day. Let me know what happens.
> 
> Pictures if you got them.
> 
> Thanks.


Did you hook up your thermostat yet? I haven't and wondered how you did yours?
[/quote]

No I haven't yet. Camper is in storage down the road and haven't brought it home yet. I'll be heading to WV this weekend to fish up on the Greenbriar out past Elkins. When I get back I plan on bringing it home to install the thermostat. I'll keep ya posted and take pics.


----------



## Stumpy75

I just replaced my thermostat on my 2014 210TRS. The wires matched some wires from the trailer, but not all. And if you just disconnected all at once, you could really get them messed up.

Here's what I found:

Purpose / Thermostat / Trailer

12v Pos / Red / Green
12v Neg / Blue / Blue
Furnace / White / Black
Fan Lo / Gray / White
Fan Hi / Green / Green
Compressor / Yellow / Yellow

I cut off one wire at a time on the analog thermostat, and made sure I hooked it to the correct color on the digital one. I also marked each wire with tape, as to the function.

I did have a problem finding wire nuts small enough for the small gauge wires that are used, especially on the trailer. I ended up using bell wire crimp connectors(made for 22 to 18 gauge).


----------



## CaptFX4

wv outbacker said:


> I ordered this same thermostat and should be here any day. Let me know what happens.
> 
> Pictures if you got them.
> 
> Thanks.


Did you hook up your thermostat yet? I haven't and wondered how you did yours?
[/quote]

Finally brought the Outback home today and installed the digital thermostat. Wire for wire install for me maybe 10 mins because I had to chase the kids around as I was doing it. Turned it on and everything worked great. I'll see if I can load a pic in the next couple of days.


----------



## wv outbacker

CaptFX4 said:


> I ordered this same thermostat and should be here any day. Let me know what happens.
> 
> Pictures if you got them.
> 
> Thanks.


Did you hook up your thermostat yet? I haven't and wondered how you did yours?
[/quote]

Finally brought the Outback home today and installed the digital thermostat. Wire for wire install for me maybe 10 mins because I had to chase the kids around as I was doing it. Turned it on and everything worked great. I'll see if I can load a pic in the next couple of days.
[/quote]
It would be great if you could post a picture..still haven't got to mine yet.


----------



## Stumpy75

Here you go...

I tagged the wires that came from the trailer with what the old thermostat was. The unmarked blue wire is 12v Neg. I then transfered wire to wire with the new thermostat. The old thermostat was hanging below this pic.









New one hooked up and mounted. The mounting screw holes even lined up!


----------



## CPan

Stumpy75, Did this upgrade allow for the use of the AC fan when using the Furnace?

We've been doing some winter camping and would like the fan to move the warm air inside. The way the stock thermostat in our '14 230TRS works is that the AC fan doesn't engage if in FURNACE mode.


----------



## Stumpy75

CPan said:


> Stumpy75, Did this upgrade allow for the use of the AC fan when using the Furnace?
> 
> We've been doing some winter camping and would like the fan to move the warm air inside. The way the stock thermostat in our '14 230TRS works is that the AC fan doesn't engage if in FURNACE mode.


No, it does not allow the AC fan to run in furnace mode. This is a direct replacement of the original analog with the digital thermostat. It works the same, but it's just digital, which has a lot better temperature control.

The limited cold weather camping I've done so far, I just used a small fan pointed toward the ceiling to circulate the heat better.


----------



## CPan

I just now put in a digital thermostat. The 10 degree swing bothered me so much I couldn't take it anymore. Thanks for your reply. I wonder why it blocks the ability to use the fan on the A/C to circulate the site. Maybe to avoid blowing fuses?

For wiring on my 2015 Outback 230TRS it was color for color except grey to white, red to green, white to green/black. Colors are thermostat to wall.


----------

