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paulbeauchemin's avatar
Aug 04, 2017

blowing fuse on power line to trailer

I have a 2017 Jayco Pinnacle 5th wheel pulled by a 2015 F350.

The jayco is about 5 weeks old. Took a trial trip in June and noticed that the batteries were a third dis-charged after towing all day. Had the trailer at the dealer and he said- your truck fuse is blown that provides power to the trailer.

Well had my mechanic replace the 25 amp fuse and sold my house and left town.

The fuse has blown again and I am not sure of where to look as to the root cause. Assume something in the trailer is shorting it out. No option to take it to the dealer since I am hundred of miles away and going south.

Not a big deal if I am going to campgrounds, but I've had to dry camp a couple of times overnight and I worry I won't have power

What would anyone suggest I do?
  • Is 25A the right size fuse?
    Seems like they're usually 40A?
    I would verify the size needed and learn how to replace it myself.
    Also, I would verify that the relay is installed for charging trailer batteries. It may have been missing all this time as Ford doesn't always include it for some reason.
  • Is 25A the proper fuse? I could easily see a large discharged battery bank pulling more power than that. I think GM, for instance, uses a 40 amp fuse. I'm not suggesting you just stick a bigger one in there but I would make sure that's really the correct size. Does it blow right away? If so that would indicate a direct short. If it takes some time later it's likely an overload or a wire that has an intermittent short. Intermittents are difficult to find, you just need to start inspecting the wiring.

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