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lantanatx's avatar
lantanatx
Explorer
Jun 04, 2015

Electric jack blowing fuse

Picked up my new Jayco Jay Flight 23mbh yesterday and got home and could not unhitch because the electric jack wasn't working. It had blown the 30 amp fuse. Even when we replaced the fuse, the light worked but the jack didn't so I took it back this morning (70+ mile one way) and they swapped out the jack. We used the manual crank handle at the dealer to get it unhitched and they swapped out the jack while I ran some errands. Worked fine when I hitched it up at the dealer but 2 hours later at home - it moved about 1/8th of an inch and blew the fuse again.

Had to come into work this afternoon so my sister loaned me her car, so I just left it to deal with this evening. What is going wrong here? The only electrical modification I had made to the TT was adding a battery disconnect switch - could that be related somehow (it was always in the ON position)?

17 Replies

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  • pira114's avatar
    pira114
    Explorer II
    Jun 04, 2015
    I'm gonna second the bad ground. Since it's new, I bet they didn't get a good bite on the star washer. Lots of paint to get through. Check that
  • lantanatx's avatar
    lantanatx
    Explorer
    Jun 04, 2015
    No change of directions. It literally blew a fraction of a second after I put my finger on the switch to go down. It was not run up too far or down too far either. I see on the Jayco owners forum some other people are having similar problems.
  • GordonThree's avatar
    GordonThree
    Explorer
    Jun 04, 2015
    colliehauler wrote:

    The only other thing is to make sure it has star washers that bite into the metal where the jack is mounted, that is the ground on the jack.


    ^^^ This. If you have a bad ground, jack will struggle and blow fuses. I went through three fuses before I discovered this. Pull the screws out, clean the contact between jack and frame, tighten screws. Presto :)
  • colliehauler's avatar
    colliehauler
    Explorer III
    Jun 04, 2015
    Did you change directions on the jack before letting the motor come to a complete stop? I know on my jack if you do not let the motor come to a complete stop before changing directions it will blow a fuse everytime.

    The only other thing is to make sure it has star washers that bite into the metal where the jack is mounted, that is the ground on the jack.
  • lantanatx's avatar
    lantanatx
    Explorer
    Jun 04, 2015
    I just got the trailer yesterday so it is a brand new battery that had been hooked up to electric for several days. The battery worked the slide and lights. Besides, if I'm hooked up to my truck won't the truck battery compensate if for some reason I got a dud as a battery?
  • westend's avatar
    westend
    Explorer
    Jun 04, 2015
    Yes, your battery is probably discharged. The disconnect switch should be in the "off" position when stored. Either jump the battery or recharge it and you should have a working jack. You need the switch in the "on" position while charging from the trailer's onboard converter.

    BTW, a handheld meter is a good thing to have for an RV.

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