2012 Discovery 36J A/C Temp Sensor Location

[pagosajoe]

We have a major issue with the designed location of the temperature sensor for the front A/C in the cabinet on the left side over the driver's head. Obviously Fleetwood needs a lesson in thermodynamics.

Because the sensor is installed in a closed cabinet that is attached to the outside wall that collects and stores heat, the sensor dutifully reports the much higher temperature (to which it is exposed) to the A/C thermostat, and the A/C dutifully follows the thermostat's requirements.

The issue is that from the beginning of the day, the temperature is very comfortable when the A/C is set to 72-74 degrees. As the day progresses, to maintain a relatively comfortable environment, we must continually move the thermostat setting higher and higher to turn off the A/C, until, at the end of the day, the thermostat is set to 90 degrees, which is the limit setting for cooling. Otherwise, we're frozen out, as the thermostat believes the sensor is telling the truth (it is), and keeps trying to cool the front of the coach.

The next day, we repeat the process, presuming we remember to turn the thermostat back to a comfortable 72-74 degrees, otherwise the A/C won't turn on until it gets up to 90.

If anyone has a solution for this issue, we'd love to hear it. I've tried insulating around the sensor in the cabinet, with no luck. Relocating the sensor may be a solution, but it would leave a hole in the cabinet -an easily resolved a problem if the issue of comfort would be corrected.

We love our 2012 Discovery 36J, but there are some niggling little issues that the folks at Fleetwood simply didn't get "right".

[CLIFFTALL]

Here is link to a few previous threads. Hopefully they will be helpful.

http://www.google.com/search?q=Movin...earch=irv2.com

[pagosajoe]

Originally Posted by Clifftall

Here is link to a few previous threads. Hopefully they will be helpful.

Moving Thermostat temp control - Google Search

Thanks Cliff! You're on to something - I can use that info. Appreciate your assistance!

Joe

[CLIFFTALL]

Have you asked FW ?

[Triker56]

You may find other 2012 owners here

[pagosajoe]

Originally Posted by Clifftall

Have you asked FW ?

Chatting by email - will post a reply, if there's information others can use. I did remove the sensor from the cabinet - looks like an easy job to relocate it if the wire (two conductor) can be hidden to move it elsewhere. In the interium, I'll operate the system with the sensor pulled out about a foot and moved away from the cabinet to see if it makes a difference.

[pagosajoe]

Originally Posted by Triker56

You may find other 2012 owners here

Thanks - checking in with these good people as well...

[pagosajoe]

Got a response from Fleetwood:

First thing I would like you to try is removing the two screws holding the thermister to the cabinet and pull it away from the overhead cabinet about 6 inches and see if the condition still exists. That will tell us if the thermister has failed or it is reading the heat in the cabinet. If it starts functioning to read the interior ambient temperature, additional insulation would be the only option we can suggest, with the possibility of securing the insulation in place in the hollow area of the cabinet with reflective furnace tape. Relocating the thermister is hampered because of the slide-outs in the front of the motor home.

I've already pulled the sensor out of the panel before I got the note from Fleetwood and will give it a try - sounds like Fleetwood is basically saying - tough - we designed it that way. If the sensor is broke - fix it.

[gMw]

Joe, Thanks for posting this.

We haven't had the Expedition out yet in any really hot weather, but we have experienced issues in cooler weather with the placement or the front an rear thermostats. The location of the front thermostats is identical to the Discover.

That said, we'll be at Fleetwood Service the end of this month having several items looked at, one of which is the location of the thermostats. Here's the text I sent to Fleetwood's Service Rep..


Thermostat Placement – Issue(s) that we are seeing with our 2013 Expedition.
Having camped out when the outside temps have fallen into the low 30's or below,of course we ran the gas furnace to keep warm. We've noticed that the front and rear temperature sensors don't seem to be in ideal locations. Let me try to explain…
Front temperature sensor:
The front temperature sensor, which is mounted on the driver's side overhead cabinet, next to the point where the full wall slide is, always 'thinks' it's colder inside than it actually is. So the heater runs almost constantly. Making the front area warmer than it needs to be.
We've learned if we set the front thermostat at 64 degs, the front gas heater maintains a temperature inside the front of the Expedition at 69 degs. Or stated another way, the actual temperature inside the front area of the motorhome was 5 degs above the thermostat's setting.
Rear temperature sensor:
The rear temperature sensor faces the bedroom and is mounted to the cabinet wall above where the ‘front’ gas heater is mounted (for the living room, dining room, & kitchen), and always 'thinks' it's warmer inside the rear area than it actually is. My best guess is the running/cycling of front heater warms the cabinet/bedroom wall and 'tricks' the temperature sensor into thinking that it's warmer than it actually is. Example, at night we cut back the inside temp, since we want it to be 67 deg, we set the front thermostat to 62 deg's, which keeps the front at 67 deg's. The Rear Thermostat thinks it's 75 deg’s (due to heat transfer between the front heater cabinet and the rear temperature sensor), so the rear heater never cycles on, which lets the actual rear temp fall below 60 deg's (actual temp varies with the outside temp). So the rear bed and bath rooms are always cooler than desired. If I try setting the rear thermostat to 76 deg's, than it tries to maintain a temp of 76 deg’s, tooooo hot for us.

The feedback we've gotten from Fleetwood is that they'll take a look at the issue...

BTW, I added spacers behind the rear thermostat, which made no difference (With the location of a closet door, couldn't space it out tooo far).

[pagosajoe]

Originally Posted by gMw

Joe, Thanks for posting this.

We haven't had the Expedition out yet in any really hot weather, but we have experienced issues in cooler weather with the placement or the front an rear thermostats. The location of the front thermostats is identical to the Discovery...

[snip]

BTW, I added spacers behind the rear thermostat, which made no difference (With the location of a closet door, couldn't space it out tooo far).

Hi George,

You're welcome - and thanks for sharing your experiences too! We're headed out on the road in about 10 days for a trip, and will check out how the A/C works with the sensor exposed, rather than being in the cabinet. I don't believe it's a failure of the sensor, but a failure in the design. Currently, I have the sensor taped to the small overhead goose neck light above the driver, so it's exposed to ambient air, rather than the heated air in the cabinet.

Please post the results of your experience, and I'll do the same after our trip.

Cheers,

Joe

[gMw]

Hi Joe,

I agree with you that it's not a sensor issue, it's a sensor placement issue .

We're heading out this weekend for a short trip (about 1,000 miles round trip). The motor home will be parked in a shaded site with the driver's side facing North/East, which should help some, for the 1st part of the trip, and in a sunny sport, with the driver's side facing south for the second part. So I'll have a comparison. Should there be a problem, I'll try your idea of taping the front sensor to the small overhead goose neck light above the driver's seat

We'll be at Fleetwood the week of July 29th, will post the results.

Safe Travels,

[FRR2EYW]

George and Joe,

I am having the same issue with our 2011 Expedition. I'll be interested in hearing what Fleetwood says also. This winter in the keys, the coach was facing west, which means the sensor was on the south wall. We had an issue with the coach being too cold. I hadn't gotten around to doing any research, but please let me know what you find out.

[bruceisla]

Who is the manufacturer of the A/C ?

[gMw]

bruceisla, Our Expedition has two Colman Mach ACs, rear one being an AC/Heat pump. We have no issues with the ACs themselves.