DIY 2nd AC unit success

Major Malfunction

Advanced Member
Joined
Jun 23, 2014
Posts
68
Bought my 2023 Cougar 29RLI with one AC unit which I said to myself I would never do again 2 trailers before that. Has the optional pre-wired vent in the front bedroom with the infamous stickers for part numbers 597263 gateway and 661579 AC unit that basically do not exist. I also have the InCommand system that woudl allow you to run both ACs from the touch screen provided you get the correct gateway, etc.

I successfully reverse engineered what was needed and installed it all over the weekend. All is well and wanted to share what I used and how I did it since when I researched this same topic, it seemed everyone was as puzzled as I was on how you can actually do this on your own.

Also, I did take it to my local RV dealer I have been dealing with for over a decade. They quoted FOUR THOUSAND SEVEN HUNDRED DOLLARS for the AC unit and to install it. I paid a little over $1400 retail for EVERYTHING and did it myself in a few hours. The hardest part to the whole install is getting the AC on the roof.

I have a Coleman Mach Q and that it is ridiculous quiet compared to any AC unit I have had in any of my trailers. I wanted the same in the front bedroom. If you have InCommand or any other type of CAN-BUS system (also known as RV-C) that lets your touchpad talk to the equipment in the trailer, you MUST get a gateway that is matched to that brand AC unit. That being said there are Dometic gateways, etc. This is the interface board that allows the AC to talk back and forth with the InCommand. If you want to just install an AC unit and use the manual knobs on it, you can do that without a gateway and literally just put it on teh roof and hook up a few wires.

This is all DIY and my experience. NO warranty, etc implied. Also, PLEASE be sure the breaker is off before trying to uncover or work on any wiring!

For the Coleman, there is a combination gateway that handles the 120v and 12v power sources, the freeze detector, the room temp sensor, and the CAN-BUS plugs. That is part number "9430-754 | Cool Only Net Zone Control Kit for iNCommand or RV-C". You connect the existing wires that are tucked away in the ceiling to it. The only wire that I had to splice was a 12v source but everything else is ready to go. You do have to use a hole saw to make a passage to the blanked out box where the 120v wires are waiting.

For the CAN-BUS, you go to your original AC unit. There is a bus wire and a terminator plugged into it. You take out the terminator and there should be an extra 4 pin wire harness hanging there. You put that into where the terminator was. That wire will lead back to your new AC unit with the rest of the wires. You take that 4 pin harness and plug that into your new gateway and then the terminator you took from the other gateway now goes in this new gateway. This adds the new gateway to the bus back to the InCommand.

I got a 15K Coleman Mach Q. 48209-0650 and specifically made for ducted ceilings. Obviously, that is important if you want to work like that. In addition, you need a duct divider 8430-3062 to seal off the return from the supply side inside the AC unit. And finally you need 8430-5501 which is the duct assembly that goes on the ceiling inside the trailer where the air filter goes, etc. The one I have matches my original AC unit and I particularly like it has a 12" furnace filter in it rather than that ratty screen fabric. You get what you want but that is what I did.

Getting the old air vent out and all the sealant off the roof was tedious. Once cleaned, covered with 4" wide endurobond tape. Set the AC unit over this, mounted the metal ring plate inside. Run 4 bolts through it and into the rooftop AC unit. Tighten down equally a bit at a time until you squash the AC unit gasket down to the tell markers (about 1/2"). Connect the rest of the wires to the gateway, which is pretty straight forward. And then the gateway actually hangs on 2 threaded posts inside the AC unit specifically desgned for it. Great stuff and/or foil tape all around the inside of the unit and the hole in the ceiling to prevent outside air from getting in and allowing it to blow into the roof openings rather than your duct work. Last step is to connect a 9 pin plug in green mesh from the AC into the gateway and that's it.

If you made it this far, flip the breaker back on for your 2nd AC unit. You should end up being able to see InCommand now actually show a room temperature for the front bedroom AC (assuming this is where you installed it). If so, turn on the fan. If that works, then turn to COOL and it shoudl work as expected. At least, that was my experience.

Ordered all my stuff through RV Products Shop. A little over $1400 and took 5 weeks due to it being on backorder and/or custom parts request.

8430-5501 | Keystone White Ducted Plenum / Ceiling Assembly
SKU: 8430-5501

9430-754 | Cool Only Net Zone Control Kit for iNCommand or RV-C
SKU: 9430-754

8430-3062 | Duct Divider for Keystone Plenums
SKU: 8430-3062

Coleman-Mach | 48209-0650 | 15,000 BTU | PowerSaver | 120V Air Conditioner | Ducted Quiet (DQ) | Polished White
SKU: 48209-0650

Again, if you have a Dometic or some other brand, you woudl need a different gateway but its all about the same in the end to install it. I've attached some pictures of the gateway, duct work, etc. Hope it helps someone!
 

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I installed a 3rd AC on mine. Similar experience and similar parts. I did not duct it, I wanted the unit to dump in the kitchen area. It's amazing how much more air you get from a dump unit vs a ducted one. I will have to say the camper was ready wired for the 3rd unit. In Command was also pre-programmed.
 
Awesome! It's kind of straight forward to put in the AC but that "gateway and AC unit" sticker seems you on a wild goose chase trying to tie it into the In-Command. I did do the golf ball thing into the plenum to expand the chase and that did make a difference. It's a shame it's this complicated to make it comfortable in a trailer!
 
One other thing to mention. There are different gateways to match different types of AC units if you get a heat pump, too. Again, RV Products website had it all off you search or call them. In addition, if you do have a heart pump unit, you can set the In-Command through the menu to know if it's cool only or gas/electric heat per unit.

And one last thing. The original AC unit was set as Unit 2 on its dip switch. A new gateway defaults to Unit 1 or if the box and turns out that what the In-Command wanted to identify it correctly.

Directions in each part box does explain the minutiae if you take time to read it. But obviously you need the right parts in order to get the right directions. Even when I contacted Keystone they couldn't give me any retail equivalent of what I actually needed. They were literally no help, unfortunately.
 
Adding that 3rd AC was the single best upgrade I've done so far. I should have known if the hole is there and all of the wiring and programming is done the thing obviously needs the unit added. I should have made the dealer do it. The hardest part of my upgrade other than getting the new unit on the roof was getting the existing vent fan out of that hole that they installed. Those guys love that Dicor.
 
$2,300 sounds like it is in the ballpark.

I am an RV parts dealer on the side and just bought a 2nd AC unit with all the required parts and will install it myself, but based on my labor rate and material mark-ups, my retail price to a customer would be pretty close to that with labor, maybe a bit less, but pretty close.

Really sucks because the factory option for the second AC is "only" $800-$900 when installed during the build of the unit at the factory.
 
Ordered all my stuff through RV Products Shop. A little over $1400 and took 5 weeks due to it being on backorder and/or custom parts request.

Great write up and thanks for the shoutout! I'm glad we were able to get you all taken care of!

Would you mind if I share your experience and install process on our blog in order to help others with similar installs?

-Derek
 
Last edited by a moderator:
I installed a 3rd AC on mine. Similar experience and similar parts. I did not duct it, I wanted the unit to dump in the kitchen area. It's amazing how much more air you get from a dump unit vs a ducted one. I will have to say the camper was ready wired for the 3rd unit. In Command was also pre-programmed.
Thanks for input, do you know if a ducted unit, having the ducts terminated is recommended? I am looking at doing same thing but didnt know if it was an issue since the return and supply would be on top of each other and you are limiting air flow? Thanks again for any input.
 
Bought my 2023 Cougar 29RLI with one AC unit which I said to myself I would never do again 2 trailers before that. Has the optional pre-wired vent in the front bedroom with the infamous stickers for part numbers 597263 gateway and 661579 AC unit that basically do not exist. I also have the InCommand system that woudl allow you to run both ACs from the touch screen provided you get the correct gateway, etc.

I successfully reverse engineered what was needed and installed it all over the weekend. All is well and wanted to share what I used and how I did it since when I researched this same topic, it seemed everyone was as puzzled as I was on how you can actually do this on your own.

Also, I did take it to my local RV dealer I have been dealing with for over a decade. They quoted FOUR THOUSAND SEVEN HUNDRED DOLLARS for the AC unit and to install it. I paid a little over $1400 retail for EVERYTHING and did it myself in a few hours. The hardest part to the whole install is getting the AC on the roof.

I have a Coleman Mach Q and that it is ridiculous quiet compared to any AC unit I have had in any of my trailers. I wanted the same in the front bedroom. If you have InCommand or any other type of CAN-BUS system (also known as RV-C) that lets your touchpad talk to the equipment in the trailer, you MUST get a gateway that is matched to that brand AC unit. That being said there are Dometic gateways, etc. This is the interface board that allows the AC to talk back and forth with the InCommand. If you want to just install an AC unit and use the manual knobs on it, you can do that without a gateway and literally just put it on teh roof and hook up a few wires.

This is all DIY and my experience. NO warranty, etc implied. Also, PLEASE be sure the breaker is off before trying to uncover or work on any wiring!

For the Coleman, there is a combination gateway that handles the 120v and 12v power sources, the freeze detector, the room temp sensor, and the CAN-BUS plugs. That is part number "9430-754 | Cool Only Net Zone Control Kit for iNCommand or RV-C". You connect the existing wires that are tucked away in the ceiling to it. The only wire that I had to splice was a 12v source but everything else is ready to go. You do have to use a hole saw to make a passage to the blanked out box where the 120v wires are waiting.

For the CAN-BUS, you go to your original AC unit. There is a bus wire and a terminator plugged into it. You take out the terminator and there should be an extra 4 pin wire harness hanging there. You put that into where the terminator was. That wire will lead back to your new AC unit with the rest of the wires. You take that 4 pin harness and plug that into your new gateway and then the terminator you took from the other gateway now goes in this new gateway. This adds the new gateway to the bus back to the InCommand.

I got a 15K Coleman Mach Q. 48209-0650 and specifically made for ducted ceilings. Obviously, that is important if you want to work like that. In addition, you need a duct divider 8430-3062 to seal off the return from the supply side inside the AC unit. And finally you need 8430-5501 which is the duct assembly that goes on the ceiling inside the trailer where the air filter goes, etc. The one I have matches my original AC unit and I particularly like it has a 12" furnace filter in it rather than that ratty screen fabric. You get what you want but that is what I did.

Getting the old air vent out and all the sealant off the roof was tedious. Once cleaned, covered with 4" wide endurobond tape. Set the AC unit over this, mounted the metal ring plate inside. Run 4 bolts through it and into the rooftop AC unit. Tighten down equally a bit at a time until you squash the AC unit gasket down to the tell markers (about 1/2"). Connect the rest of the wires to the gateway, which is pretty straight forward. And then the gateway actually hangs on 2 threaded posts inside the AC unit specifically desgned for it. Great stuff and/or foil tape all around the inside of the unit and the hole in the ceiling to prevent outside air from getting in and allowing it to blow into the roof openings rather than your duct work. Last step is to connect a 9 pin plug in green mesh from the AC into the gateway and that's it.

If you made it this far, flip the breaker back on for your 2nd AC unit. You should end up being able to see InCommand now actually show a room temperature for the front bedroom AC (assuming this is where you installed it). If so, turn on the fan. If that works, then turn to COOL and it shoudl work as expected. At least, that was my experience.

Ordered all my stuff through RV Products Shop. A little over $1400 and took 5 weeks due to it being on backorder and/or custom parts request.

8430-5501 | Keystone White Ducted Plenum / Ceiling Assembly
SKU: 8430-5501

9430-754 | Cool Only Net Zone Control Kit for iNCommand or RV-C
SKU: 9430-754

8430-3062 | Duct Divider for Keystone Plenums
SKU: 8430-3062

Coleman-Mach | 48209-0650 | 15,000 BTU | PowerSaver | 120V Air Conditioner | Ducted Quiet (DQ) | Polished White
SKU: 48209-0650

Again, if you have a Dometic or some other brand, you woudl need a different gateway but its all about the same in the end to install it. I've attached some pictures of the gateway, duct work, etc. Hope it helps someone!
There is a good video on you tube of adding a 2nd unit. For some reason I could not attach the short cut to it. Does anyone know if you have to install the same brand AC when adding a 2nd one? I wouldnt think it would matter? Does anyone have a preference for a brand? My Cougar has a Coleman 15k BTU but I have heard they aren't the best anymore and maybe add a different brand for the 2nd unit. Thanks in advance.
 

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