Blowing fuses

[dyurisich]

Hello to all, new to forum. Having a problem with my 99 Ford Explorer blowing the trailer running lamp 15amp fuse. All turn, brake, and hazard flashers work on trailer and truck, but when I turn on the lights on the truck, it pops the fuse for the trailer. Thinking I might have a short in the plug in wire harness thats under the truck. Its a flat 4 thats been on the truck for 3-4 years. Going to replace that harness. All trailer lights properly grounded to frame, not through hitch and ball. Anyone have any different thoughts on this? I hate trailer lights and all the problems they create.

 

[Quackrstackr]

My buddy's virtually new 3/4 ton Ram does the same thing.

 

[dyurisich]

Thanks for the reply. Any idea what might be the cause?

 

[Quackrstackr]

We haven't found it yet but I don't think that he's looked very hard. The only time that he hauls a trailer with it is when he hooks to my boat. He lives over 4 hours away so I haven't had the opportunity to chase it down myself.

 

[huntinfool]

I posted this reply on the other thread you started.

I personally have never had a plug go bad. I have, however, had several bulbs go bad that would short out the system and/or have some wiring on the trailer that was grounded out and cause the same problem. Switch out the plug and see if that fixes it, but I don't think that is the problem. I have had some plugs on vehicles for 20 years now and they still work fine.

My bet is that if you follow the brown wire on your trailer (this is the running lights wire) that somewhere along the wire there will be a worn spot where it is grounding out on the frame. Let us know what happens after the plug swap.

 

[huntinfool]

Two questions,

1. Do the fuses blow out with any trailer you hook up to the vehicle?


2. Does this trailer blow out fuses on other vehicles?

 

[Zum]

I had a problem like that awhile back.
At first all I did was put a bigger fuse in...Not saying you should.
It worked but I was worried the wires might get to hot.
I ended up just rewiring the wires on my truck,including the plug.It's worked ever since,probably had a chaffed wire.I looked alittle bit but there was so much undercoating on them that I just threw it out.

Do you have a friend with a trailer that would fit into your plug?
Try their trailer and see if you have the same problem.

 

[rebg38]

I had the same problem a few years back with a truck. Finiallly solved the problem by changing the flasher in the truck, you might look into that

 

[dyurisich]

Post subject: Blowing fuses

Two questions,

1. Do the fuses blow out with any trailer you hook up to the vehicle?


I'm not sure as this is the only trailer that I own. Bought it used on CL. Its a 1956 Norjack boat trailer that I refinished. Stripped all paint down to bare metal, primed and painted, new tires, fenders. Used the same light kit that was on it when I bought it. Was Fairly new and in decent shape. All wires are run through plastic split loom so metal contacts any possible bare spots except ground.

2. Does this trailer blow out fuses on other vehicles?

I have not tried this trailer on any other vehicles. Maybe I'll hook it up to my buddy's F150 this weekend and check.

My bet is that if you follow the brown wire on your trailer (this is the running lights wire) that somewhere along the wire there will be a worn spot where it is grounding out on the frame. Let us know what happens after the plug swap

When refinishing the trailer after taking the lights off, I did find a spot on the brown wire that was stripped of insulation. When I re-ran the wires, I ran them in plastic wire loom so the spot would not contact any metal. Do you suspect this to be the problem? Maybe causing a short and blowing the fuse? Could I put a higher amp fuse in safely? Go from a 15 to a 20?

Rebg38,
you said you changed the flasher in the truck. What flasher are you talking about? For the hazard flashers?

 

[huntinfool]

If the running light wire had a bare spot on it then it should have been fixed. You need to find that spot and cut the wire. Then strip the wire and put a butt connector or a wire nut on it and tape it up good.

Do you have the white wire grounded to the trailer?

 

[dyurisich]

If the running light wire had a bare spot on it then it should have been fixed. You need to find that spot and cut the wire. Then strip the wire and put a butt connector or a wire nut on it and tape it up good.

Do you have the white wire grounded to the trailer?

I can find that spot pretty easily and fix that. Yes I do have the white wire grounded to the trailer tongue with a self drilling screw to bare metal.
How much of the bare spot on the wire needs to be removed? Just the bare wire or go a couple inches to each side?

 

[huntinfool]

1/2 inch either side should be fine.

 

[dyurisich]

Hey there everyone. Been a while since I was able to work on the trailer but got her finished today.

Replaced the truck taillight whip connector but was still blowing the running light fuse. Replaced the trailer lights and wires and no more blown fuse. No broken wires on old kit or corroded light sockets. Must have been something internal under the wire insulation?

Was still having a problem with the right taillight after the new one was installed. No stop, and running/ turn was MUCH dimmer than the left. Suspected a ground problem. Solved by running seperate groung pigtail from taillight post to trailer frame. Did the same to left side to keep continuity. All lights working like a charm now.

Thanks for all your input.

 

[huntinfool]

Glad to hear that you got it working. Now get out there and ENJOY!