Forum Discussion

kratedisease's avatar
kratedisease
Explorer
Jul 31, 2015

Does A/C turn off automatically climbing hills ? Ford F53

I was climbing a long hill in the mountains today when I noticed that the A/C unit stopped blowing after a extended climb but turned on again after I stopped climbing and the RV up shifted to 3 or 4th gear. Even the fan blower stopped blowing. When I reached the top of the mountain I manually shut the system off with the switch and then switched it on and it restarted and worked fine the rest of the trip.

Is this normal ? I have an older F53 chassis, a 2000YR Hurricane by Thor

If so is this a power save feature that is programmed into the ECU ( electronic control unit ? )

Or is this just the system becoming overloaded and shutting down ?

Anyone else experience this ?

Please advise , thanks
  • Nonsense. Mine does not leak. Any tech worth his pay can find and fix the leak in the a/c.
  • TNGW1500SE wrote:
    I'd bet it's a vacuum leak. Find a auto repair shop that has a smoke machine and have them hook it up. The smoke fills the intake and all the lines with smoke. The leak will be easy to find.


    It is NOT a Ford Engine system vacuum leak. The aftermarket Dash AC system, the vacuum systems they use have inherent leaks. So, when the engine goes to zero vacuum on heavy acceleration or hill climbing, the Dash AC system uses up the little available vacuum. Doug
  • I'd bet it's a vacuum leak. Find a auto repair shop that has a smoke machine and have them hook it up. The smoke fills the intake and all the lines with smoke. The leak will be easy to find.
  • Class A Gasoline motorhomes have NO auto AC shut off. AS others mentioned, the Aftermarket Dash AC systems on motorhomes are Vacuum hogs. They have leaks and on heavy acceleration, when the engine vacuum goes to 0, the Dash AC blend door motors use up all the vacuum including in the vacuum reservoir. Adding a larger or extra reservoir rarely fixes the problem. The best result if you are always in hill climbing or lots of times you are driving at high speeds and lose vacuum, you install the same 12 volt vacuum pump the Diesel chassis's use. That way you will always have the needed vacuum. The AC is NOT shutting OFF, the Compressor and fan motor is still running, the air just comes out the defroster vents. Once the vacuum is restored the blend doors close and the air then comes out the dash AC vents. Doug
  • I've seen the same thing on cars. On my 87 mustang there was actually a switch on the accelerator bracket that shut the a/c compressor off when you pushed the pedal down so far. This allows more power to the drive train.
  • Yup, its a lack of vacuum issue. The (2) options are;

    1) Live with it

    or

    2) Add in a larger vacuum reservoir.

    Me personally - I'd live with it.
  • I used to have a van (dodge ram van) that had a similar issue. I could change where the air came out (defrost, dash, or feet) by backing of the gas and then stepping on it. When going up a hill it would switch and all I had to do was the above routine until it went back to the vent I wanted. Kind of funny, kind of annoying, not worth the hassle to fix.
  • It's not uncommon on the E series vans (at least those with the same v10 as the F53) to develop vacuum issues in the system that controls the ventilation "doors". My E350 has experienced that a couple of different times over the years...where at times the engine is under heavy load like climbing hills, the blower doors close, sending the air either to the defrost or nowhere. Sounds like what you might be experiencing.