Furrion AC Temp Sensor Relocation: Alternative, parts-free method

uwskier

Senior Member
Joined
Jan 11, 2022
Messages
440
Location
Arizona
If you have a Furrion AC unit, you've certainly noticed the temperature fluctuations, especially if you try to use the heat without running the fan. Sticking the temp sensor through the filter media helps somewhat, but your AC may short-cycle with this configuration. The correct thing to do is relocate the temp sensor. GD will send you a free relocation kit if you ask support, but that involves running wires and finding a place to poke a hole.

The wiring from the Furrion wall controller to the roof unit MAY (your system may be different) include extra conductors depending on what Grand Design had available at the time they built your unit. In my case, I had extra conductors so I went ahead with this relocation method. Here's what I did.

disclaimer: do this at your own risk. It's not hard if you're used to working with small gauge wiring.

credit: [MENTION=36230]BigDinMB[/MENTION] for astutely noticing the extra conductors and asking if anyone has ever tried this

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Step 1: Identify your wire bundle in your roof unit. Mine had three extra wires. We'll use white and yellow for our task today.

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Step 2: Remove the wall unit. It comes off with a quarter turn lefty loosey. I also removed the backing plate as seen here since I needed to enlarge the factory hole in the wall slightly to get all those big blocky splice connectors out. (yes, my slide is only partly open... shame on me...)

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Step 3: Isolate your spare conductors and strip away any outer insulating jacket to free up some slack.

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Step 4: Cut off the existing temp sensor with enough slack on both ends of your cut to make some splices. No turning back now! Strip and splice the wires together. Splice each conductor individually, then optionally shrink wrap the whole works together for added strength. I used heat shrink solder connectors you'll see in subsequent photos. They work great.

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Step 5: Splice your temp sensor leads to the remote ends of your spare conductors. I used heat shrink solder splice connectors but butt connectors would probably work too. The conductors in the wire bundle are not braided though and I don't like butt splicing solid conductors when solder is a thing that exists.
 
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Step 6: TEST! Body heat works well. The sensor temp should rise pretty quickly if you give it a light squeeze. GREAT SUCCESS!!!!

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Step 7: Put everything back together and clean up. Grab a beer and tell your wife what a studly man you are. When she finishes laughing, reminder her that she'll be happy when the heat and AC works better next time.

I don't have unfettered access to my wall controller (you can probably call it a thermostat now) where I park since I can't open my slide all the way, so I just left the sensor there as a tail for now. I'll figure out a way to make it look better on our next outing. I think I'll drill a small hole right below the controller and have it protrude there. That or I've thought of housing it inside the controller itself and fabricating a plat that holds the controller away from the wall slightly to let airflow in. TBD.

Thanks for reading!
 
View attachment 39910
View attachment 39911
Step 6: TEST! Body heat works well. The sensor temp should rise pretty quickly if you give it a light squeeze. GREAT SUCCESS!!!!

View attachment 39912
Step 7: Put everything back together and clean up. Grab a beer and tell your wife what a studly man you are. When she finishes laughing, reminder her that she'll be happy when the heat and AC works better next time.

I don't have unfettered access to my wall controller (you can probably call it a thermostat now) where I park since I can't open my slide all the way, so I just left the sensor there as a tail for now. I'll figure out a way to make it look better on our next outing. I think I'll drill a small hole right below the controller and have it protrude there. That or I've thought of housing it inside the controller itself and fabricating a plat that holds the controller away from the wall slightly to let airflow in. TBD.

Thanks for reading!

Our control is in the master bedroom. What will that do for the bunkhouse area? Seems like you would want it in the center of the camper so everyone is comfortable. Plus if you have your master bedroom door closed the temperature will be a lot different in the other rooms. I’m going to leave mine hanging out of ac. It seems that’s the best place.

2400bh


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Our control is in the master bedroom. What will that do for the bunkhouse area? Seems like you would want it in the center of the camper so everyone is comfortable. Plus if you have your master bedroom door closed the temperature will be a lot different in the other rooms. I’m going to leave mine hanging out of ac. It seems that’s the best place.

2400bh


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Interesting they put the controller in a bedroom. On mine, it's in the main living area. Would have expected the similarly laid-out 2400bh to be the same.
 
Interesting they put the controller in a bedroom. On mine, it's in the main living area. Would have expected the similarly laid-out 2400bh to be the same.

So you have a 2400bh?

2021 2400bh
Never mind i see u have a 2600

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Following up on this: AC works like it should have from the factory with this mod. No short cycling, and accurate temperature. Heat cycles on and off too much since the heat outlet is right below the sensor (basically). Need to ensure you have something in the way like a trash can or something to help redirect the warm air out into the main cabin a bit more.

But all-in-all, I'm very happy I made this mod. We typically don't use the heat anyways and use space heaters if we need them.
 
thanks for this. Just did mine this afternoon. works great.
we have a 2600rb also, I had the extension kit from Grand Design, the only part I used was the round screen sensor housing, mounted the sensor just above the tstat.
 
Thanks for this detailed instructions! Will be doing this tomorrow barring I have the extra wires in the bundle!
 
Excellent instructions and great insight on taking advantage of the unused conductors.

I changed the process a bit by cutting up the sensor extension harness from GD and used it on both ends rather than cutting the temperature sensor cable. Completely reversible install if, for some reason, it needs to go back to original.

Thank you for opening my eyes to this great fix.
 
thanks for this. Just did mine this afternoon. works great.
we have a 2600rb also, I had the extension kit from Grand Design, the only part I used was the round screen sensor housing, mounted the sensor just above the tstat.

Does anyone happen to know the GD part# for the temp sensor extension/relocation kit? I called customer service and was first told I'd have to take it to a dealer, have it inspected, approved by Furrion, etc... when I pushed back, I was asked for part# so I could be sent the correct part.

Thanks,
Tom
 
Honeywell

Does anyone happen to know the GD part# for the temp sensor extension/relocation kit? I called customer service and was first told I'd have to take it to a dealer, have it inspected, approved by Furrion, etc... when I pushed back, I was asked for part# so I could be sent the correct part.

Thanks,
Tom

Honeywell make a wall mountable 10K temperature sensor that looks a lot better than the bulb hanging. Just search for 10K ohm NTC Type II thermistor wall mountable. We use these for remote temperature sensing on commercial buildings. Its what I installed on my two units.
 
Make sure it is a linear design.

Does Furrion really use linear thermistors in their units? Seems like they'd use the more plentiful non-linear.

That button is NTC but non-linear so it'd probably be less accurate the farther it got from 77F nominal. Bummer. That'd be an excellent solution for those without spare conductors to relocate the factory thermistor. Poke a hole in the ceiling and make the short run into the plenum.
 
Our control is in the master bedroom. What will that do for the bunkhouse area? Seems like you would want it in the center of the camper so everyone is comfortable. Plus if you have your master bedroom door closed the temperature will be a lot different in the other rooms. I’m going to leave mine hanging out of ac. It seems that’s the best place.

2400bh


Sent from my iPhone using Tapatalk

Good Afternoon uwskier. I noticed this weekend that my main A/C unit was not "acting" like it should and would just cycle on and off and never get the main living area cooled down to the set temp.. After reading this, it makes sense now, why. I have 2 units but the unit in the bedroom has a built in thermostat and I only have the one wall controller unit like you show in the pics. I plan to investigate my unit to see if i have unused wires also. In your case of using the white and yellow wires, does it matter which one is used on which black wire, for the temp sensor,. on either end? Thanks
 
Good Afternoon uwskier. I noticed this weekend that my main A/C unit was not "acting" like it should and would just cycle on and off and never get the main living area cooled down to the set temp.. After reading this, it makes sense now, why. I have 2 units but the unit in the bedroom has a built in thermostat and I only have the one wall controller unit like you show in the pics. I plan to investigate my unit to see if i have unused wires also. In your case of using the white and yellow wires, does it matter which one is used on which black wire, for the temp sensor,. on either end? Thanks

Doesn't matter which wire goes to which lead. Good luck!
 
Okay, so I moved the room temp. sensor per the instructions and pics that are on this thread posted by Uwskier. It worked! I didn't have the luxury of the long wires in the harness though. I was unable to get the wire harness to come out of the wall very far. The A/C unit appeared to work like it is designed though. Set the temp, it will cool down to the set temp and then start cycling to hold it. Previously it was never cooling the room down to the set temp. before it would start cycling on and off. I still think the actual temp. is off. The temp on my multi meter never matched what was on the thermostat. Not a big deal to me though. As long as the A/C will create "freezer-like" conditions.....:cool: inside my trailer, I'm good with the small temp. differences.
 
Thanks for this, I just picked up my 2024 2670MK and I thought something was wrong with the AC units. Temp was showing 64 and it was really 80 degrees. Now I know the fix.
 
Ok, uwskier, a little confused...you use the yellow and white wire in the roof....are they spliced together there? Then find the yellow and white wire running to the "thermostat" and that's where you splice in and re-connect the temp sensor. Sorry, just trying to an overall view of how it works!

Thanks!
 

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