Cockpit AC fan control is a mystery

mcr1010 · 05-30-2016, 12:44 AM

On a recent trip with the console AC running and fan on any speed, the fan would stop blowing when the Vegas started up an incline like an overpass or small hills like we have here in FL. The fan would resume blowing at the crest. Almost like it has a tilt switch controlling it. Any ideas?
Thanks

JamieGeek · 05-30-2016, 12:51 AM

Vacuum leak?

mcr1010 · 05-30-2016, 01:23 AM

If it is a vacuum leak, I don't think I could track that one down. Would be a tough one to find. May take it by the Ford service center and see if they can diagnose it. Not sure if putting a disconnect switch on the chassis battery had an effect, but it was ok before I installed the switch.

JamieGeek · 05-30-2016, 01:25 AM

I have a disconnect on both batteries and A/C works fine--needed it all day today.

Jegdrum5050 · 05-30-2016, 10:44 AM

My class c had the E450 and it always slowed A/c down going up an incline then would be normal on the way down. Someone said that was for max power going up. Always thought it was normal.

mustang94 · 05-30-2016, 01:59 PM

Sounds more like there is a lose wire going to the fan motor. Going up hill the wire falls back and loses connection until you level back out again. Sitting still with fan on high go to where you fan is at and slowly start moving your wires towards the back of the MH, you might hear the fan stop. You might even want to check out a few under you dash as well.
Some vehicles do have the AC shut off for max power going up hills but not the fan motor it self and the fan motor is 12 volts dc and not vacuum operated.

sanpere/carter · 06-18-2016, 11:39 PM

I'm having the same problem too! Leaving for the west and long hills that the fan will not be running as I go up. Took it to an RV repair center yesterday to find out why it wasn't blowing cold air. They added a little freon but it didn't seem to increase the cooling of the air and, of course, the fan still stops on the uphill.

Hoping desperately that someone can come up with a solution soon.

mcr1010 · 06-19-2016, 12:38 AM

I haven't had a chance to do anything with my air shut off problem as yet. I did some messing around with it while driving and found that it is not necessarily the AC that cuts out or the fan, but most likely the dash vents are closing or the direction damper is shifting. I don't think the fan is shutting off.
When placing the selection on Vent or AC I still get no air out of the dash vents when going up hill.
I am going to check the area where I installed a disconnect switch on the neg. bat. terminal again with a mirror. It may have caused a vacuum line to become pinched or disconnected. If that is not a problem, I will head out to the Ford service center and see if they can find the problem.
I did a little searching on net and found some folks had a similar problem and was it vacuum related. Makes sense as the dampers are controlled by vacuum, but what threw me off was trying to relate how vacuum could be connected to fan or blower causing it to stop.
If I find anything I will post results.

sanpere/carter · 06-19-2016, 01:31 AM

Thanks for those insights. We'll look into the damper possibility and hope to hear more from you as you learn more.

petef · 06-19-2016, 05:23 AM

Thor uses a box system made by Evans. It gets tricky as to who covers who warranty. Evans system is fed via the Ford AC system. But in the case of the fan going dead, that is a Ford issue and warranty. The fan should run no matter what. If the air coming out is not cool then it gets split between Ford and Evans,, in my case I had to have Ford install a new compressor that was leaking, then an Evans dealer fixed the a/c problem of MAX air going up thru the window vents instead of console vents. Took weeks to get it all right,, the first Ford dealer had the rig for 4 weeks, took it for a test drive and told me every thing seemed fine... no testing, no diagnostics. And it went in for handling and a/c.. they charge my $336 because they found no "problems", so nothing covered under warranty... Thor paid the bill but ultimately I had all the stuff fixed at various dealer and shops..

mcr1010 · 07-04-2016, 01:38 PM

Reporting back.
If you are having trouble with your cabin AC blower stopping while going uphill or a slight grade, you can try this for a "maybe" fix.
I put mine in stowage for a week or so with the neg. battery terminal disconnected with switch. Dropping the connection could possibly have allowed a controller to reset hopefully.
On start up, everything went well, drove out and found the steepest hill or rise available- no hills to amount to much around here. Brought it up to around 55-60 in 5th gear and the blower kept blowing going up the grade. This is not a good test as the grade was not as steep as I would have liked, but it does look promising. On my last trip when the problem started, I did not think to check if the blower was actually stopped or if it was the damper/flaps changing the air flow from the dash to another area.

A little history; all was well before installing battery switch a month or so ago before last trip. While installing the neg. battery switch, there was a few arcs and sparks which may have messed up a controller. This did note that with everything in the rv turned off there is still a parasitic draw on the chassis battery.

Gelmore · 07-04-2016, 03:37 PM

Quote:

Originally Posted by mcr1010

On a recent trip with the console AC running and fan on any speed, the fan would stop blowing when the Vegas started up an incline like an overpass or small hills like we have here in FL. The fan would resume blowing at the crest. Almost like it has a tilt switch controlling it. Any ideas?
Thanks

WE had the same issue and discovered that it was a lose wire and nothing more......hope this helps you.

Gelmore · 07-04-2016, 03:38 PM

WE had the same issue and discovered through a mechanic that it was a lose wire under the passenger side, problem solved...hope this helps you

mcr1010 · 07-04-2016, 04:26 PM

Good to know about loose wires. Will check on that also, if problem not solved.
Thanks

scrubjaysnest · 07-04-2016, 06:13 PM

Hope we don't get into the he said she said on Wed when we take the MH into the Ford dealer for the dash A/C. According to CW of Marion the blower comes under Thor warranty, ours works ok, but the compressor is under Ford warranty.

mcr1010 · 07-04-2016, 09:14 PM

Scrub, since you said Marion, are you taking it to Ford in Ocala? Reason I asked is that when I had the infamous burnt trans cable, Ford of Ocala gave me a lot of complications that it was Thor, not Ford and they would charge me etc.
So, I took it to Ford near Leesburg and they happily fixed it in record time under warranty. Hope your service goes smoothly.

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