# Carrier Airv Thermostat Conversion



## Santa Fe TX Bob

I have gone into my relay card to install a thermostate because there is so much communications problems with the remote. My remote had been working intermittantly and I was unable to reset it or get it to communicate. Reasons for changing to wall thermostat:
1. Lost Communication with remote.
2. ability to run fan during heat mode to distribute the heat more evenly within the trailer
3. frustration with Carrier and their lack of support for the unit
4. avoiding replacing an operational unit and its cost of over 1200 dollars for parts alone

Steps to install wall thermostat:
1. remove grill
2. unplug remote sensing card from the relay box.
3. cut the card off the 10-wire cable. Leave enough wire to be able to splice tie into 4 wires.
4. Yellow - compressor, red - low speed fan, Black - high speed fan, Blue - propane furnace exciter.
5. grounding these wires will make the various components start.
6. run a ground wire to your thermostat to the common terminal.
7. all wiring returning to the unit will be grounds when activated by the thermostat.

Thermostat. I am going to purchase a thermostat today. I will be looking for a battery operated unit with a digital temperature sensor. Obviously a mercury switch thermostat will not work well in a moving vehicle. Honeywell makes a thermostat with a time delay for compressor restart. That will be helpful as a loaded compressor will not start and possibly burn out if attempted to restart immediately after shut down. The factory time delay function will be eliminated in this scenario as that function was taken by the thermostat card.

Note: you will lose the function of the thermister that fits in the evaporator coil that protects against icing up. That should not be a problem if your unit is charged properly.

Legals: This is what I am doing. Do so with your unit at your own risk. I assume no liability for your unit.

Bob


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## egregg57

Santa Fe TX Bob said:


> I have gone into my relay card to install a thermostate because there is so much communications problems with the remote. My remote had been working intermittantly and I was unable to reset it or get it to communicate. Reasons for changing to wall thermostat:
> 1. Lost Communication with remote.
> 2. ability to run fan during heat mode to distribute the heat more evenly within the trailer
> 3. frustration with Carrier and their lack of support for the unit
> 4. avoiding replacing an operational unit and its cost of over 1200 dollars for parts alone
> 
> Steps to install wall thermostat:
> 1. remove grill
> 2. unplug remote sensing card from the relay box.
> 3. cut the card off the 10-wire cable. Leave enough wire to be able to splice tie into 4 wires.
> 4. Yellow - compressor, red - low speed fan, Black - high speed fan, Blue - propane furnace exciter.
> 5. grounding these wires will make the various components start.
> 6. run a ground wire to your thermostat to the common terminal.
> 7. all wiring returning to the unit will be grounds when activated by the thermostat.
> 
> Thermostat. I am going to purchase a thermostat today. I will be looking for a battery operated unit with a digital temperature sensor. Obviously a mercury switch thermostat will not work well in a moving vehicle. Honeywell makes a thermostat with a time delay for compressor restart. That will be helpful as a loaded compressor will not start and possibly burn out if attempted to restart immediately after shut down. The factory time delay function will be eliminated in this scenario as that function was taken by the thermostat card.
> 
> Note: you will lose the function of the thermister that fits in the evaporator coil that protects against icing up. That should not be a problem if your unit is charged properly.
> 
> Legals: This is what I am doing. Do so with your unit at your own risk. I assume no liability for your unit.
> 
> Bob


 Many have done this. I installed a Hunter digital thermostat. Pictures and steps are located in the Mods forum, should be under my screen name. You are not the first, nor will you be the last!

Eric


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## Santa Fe TX Bob

Thanks Eric. I had looked for this information before but could not find it.

Bob


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## radiogeek97

hi folks

not to bring up an old post but I am in this same situation. Just picked up a new to me 06 americamp trailer and it has a carrier air v with no remote. I have tryied one universal remote from amazon with no luck, and i just stumbled across this post. The unit will go into emergency cool so i know the roof unit is ok, however i cant leave it like this for my wife she wont want to get a step stool to turn it on like that plus the efault temp is too warm for her. I cant seem to find the post with the pics of the mod mensioned above. ANY pics of the mod would be a godsend. I am very comfortable with electronics so i think this mod would be Great! thanks in advance from greater boston


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## Santa Fe TX Bob

I eliminated the remote and installed a wall thermostat. previous posts should be enough information to complete the mod


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## radiogeek97

sir

i looked thru the web and did not find sufficient explanations to feel confident enough to cut into this circuit board. my carrier air v board does not have a ten wire connector inside it it it has an 8 wire and a three wire connector inside it the post above mensions ten wire connector. the 8 wire connector has all the colors mensioned. i do not have a furnace so i dont need the blue. the 8 wire connector in mine has the red yellow and black wires BUR the three wire connector has red yellow and white so i am not sure #1 if this is the right set of connectord (although these are the only large ones with multiple wres) i cant figure out how to attach a pic of what i have here otherwise i would. So if you have a link to an artle with more info Pics ect Please post it. i assure you that i am not trying to get others to do my work i have looked and failed, and just dont have the $$$ to rip out and replace a semi working ac system. im just looking for a bit of help thats all not a free lunch

thanks


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## Santa Fe TX Bob

If you look for 'Airv manual there is a link on the web - bryantrv.com/docs2/docs/airv.pdf Figure 4-10 shows the power pcb connections. You need only 2 connections plus power to operate. From this it looks like terminal 5 on your 8-wire is 'compressor', terminal 3 is power, and terminal 1 on the 3-wire connector is 'fan'. You may be able to find more information in the mods section of this forum.

Bob


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## Resqtool844

Hey Bob! Which thermastate model did you go with that has the start delay in it?


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## Santa Fe TX Bob

The time delay is a function of the AirV control board. Once the compressor cuts out the board start its timer and will not allow a restart immediately. That is to allow the refrigerant to equalize so that you are not trying to start the compressor under load.


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## Porter family

This thermostat should work for this. I will be trying it out on my 29BHS in a few days.

https://www.ebay.com/itm/8330-3362-Coleman-RV-Wall-Thermostat-for-Heat-Cool-Control-/282576959560

manual for the thermostat

http://liferebooted.net/life-rebooted-rv-files/owners-manuals/RVP%208330%20Thermostat%20Guide.pdf


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## Santa Fe TX Bob

That's kind of pricey. You can get one at the 'e-pay' for about 10 bucks. It needs to be battery operated and you run the 12v+ to the common terminal. (red) https://www.ebay.com/itm/Honeywell-Thermostats-Digital-Non-Programmable-Thermostat-Whites-RTH111B/382248086804?epid=710163402&hash=item58ffc2ed14:g:VL0AAOSwIgpZ3ST4


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## Porter family

I am wrong. Not only is it expensive but it energizes not ground the outputs so it won't work on the airv. Luckily amazon will take it back. Heading to home depot to get the one you reccomended


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## Santa Fe TX Bob

12v+ should be sent to the thermostat and it returns 12v+ to the various relays. I don't understand why you want to return ground back to your relay board. Ground is common on the relay board and 12v+ energizes the relays.

Bob


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## Santa Fe TX Bob

Apparently I had forgotten how I wired it. Regardless, if 12v+ is your common side of the relays then send 12v- to the thermostat. It matters not which direction the pixies go through the coil of the relays. I have since eliminated all but the filter grill to the AirV. My upper unit was leaking freon® so I replaced it with a Coleman HP2 heat pump. Your thermostat should have a common terminal. Which ever you run to the common of the thermostat will complete the circuit of the various relay coils.


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## pbliss

Again, not to revive a dead thread, but so far this is as close as I've gotten to some concrete information.

I took my Air 5 out, guts and all, and now have a new Dometic. Problem is, I can't figure out how to hook up the furnace again. I'm left with two two-conductor wires (a white wire, and a red wire with a white stripe on each) and a smaller two-conductor wire (green and black stripe, and black). Anybody know where these need to go???

Thanks in advance, y'all.


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## TRADER1954

We just 6 days ago bought a 2007 outback 28frls. love it, however...i can't find a thermostat to turn the furnace on. I did find the Carrier remote an it seems to have something to do with the furnace. Does my fifth wheel have a thermostat and i am blind? I've google what little i can find, nothing. Called keystone, no help. Dealorship we bought it from keeps saying there has to be a wall thermostat.

anyone out here know anything about this? any help would be greatly appreciated.

gary


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## Kubiche

I know this is an old thread but I just went through this and I believe is worth sharing.
What I have learned:
1 - Look at the diagram of the specific set up you have since there were some variations to it. I have the remote one with the added card to the relay board that contained a thermostat. 
2 - Thermostats like the Colman Mach and the AirXcel 3 buttons one wont work since they feed +12vdc and the relay board for the unit will only respond to -12vdc or ground. You will not be able to change this since the mentioned thermostats use the + and - as power for themselves and wont allow reversing of the leads.
3 - When you go with a household thermostat that is powered by batteries you are able to achieve the desired result. Since it does not care what is supplied to the R lead (which is the one usually gets connected through the leads to activate the compresor, fan etc.
4- Also home thermostats don't have a fan low and fan high options to them and so you lose some functionality unless you get creative with a 3 pos switch extra. 
5 - If going the home thermostat route please check for one that has a built in compressor protection. This is a feature that adds a time restrictions between compresor starts to prevent damage to it due to short cycles.

All this being said I used a Honeywell RTH111B as a replacement and it check all my boxes except the granular fan control ( I used the HIGH lead, I live in FL and most times that is what we go to). I am not an expert by any means but I did manage to piece the whole thing together. If anyone has any questions I will do my best to help.


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