trailer running light blowing fuse for revese lights

snowman51789

snowman51789

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I have a 2004 shore lander trailer that was rarely used by the prevouse owner (looks brand new). I've noticed that after I retrieve the boat and I'm driving home if I hit a bump the trailer running lights and the reverse lights on my truck go out. When I check I noticed it blows the truck reverse lights could this be because I am getting water in a light some were? Why is the reverse fuse blowing. I'm stumped.
Thanks
Dave
 
nlain

nlain

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Re: trailer running light blowing fuse for revese lights

Somehow I don't see the trailer running lights blowing the backup light fuse, now, trailers with surge disc brakes have a lockout solenoid that is powered by the backup light wire, 5 wire plug. There could be a short in the wire or solenoid that is blowing the backup light fuse. If the trailer running lights go out when you hit a bump you probably have a bad ground circuit, ground wire not hooked up on tow vehicle or ground wire not hooked up/bad connection on trailer. I have a 2004 Shoreland'r trailer, it has the solenoid, no problems for me so far, it had bad connection for the ground wire on the trailer that I had to fix.
 
Thalasso

Thalasso

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Re: trailer running light blowing fuse for revese lights

nlain said:
Somehow I don't see the trailer running lights blowing the backup light fuse, now, trailers with surge disc brakes have a lockout solenoid that is powered by the backup light wire, 5 wire plug. There could be a short in the wire or solenoid that is blowing the backup light fuse. If the trailer running lights go out when you hit a bump you probably have a bad ground circuit, ground wire not hooked up on tow vehicle or ground wire not hooked up/bad connection on trailer. I have a 2004 Shoreland'r trailer, it has the solenoid, no problems for me so far, it had bad connection for the ground wire on the trailer that I had to fix.
Click to expand...

Bad ground wire won't blow the fuse. It just won't work. Now a hot wire going directly to ground as in touching trailer frame when lights are turned on will blow fuse. Like if the hot wire has a bare spot in the insulation where field mice have chewed through.
 
nlain

nlain

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Re: trailer running light blowing fuse for revese lights

Thalasso said:
Bad ground wire won't blow the fuse. It just won't work. Now a hot wire going directly to ground as in touching trailer frame when lights are turned on will blow fuse. Like if the hot wire has a bare spot in the insulation where field mice have chewed through.
Click to expand...
But the ground if not good will cause the trailer running lights to go off and on, maybe I should have made that part more clear. I don't see the trailer running lights blowing the backup light fuse either, that part I think is in the circuit for the lockout switch.
 
Thalasso

Thalasso

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Re: trailer running light blowing fuse for revese lights

nlain said:
But the ground if not good will cause the trailer running lights to go off and on, maybe I should have made that part more clear. I don't see the trailer running lights blowing the backup light fuse either, that part I think is in the circuit for the lockout switch.
Click to expand...

:cool:
 
O

oregoncruiser

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Re: trailer running light blowing fuse for revese lights

I would check the wire couplings.I use the round 7 way rv plug, and the wires inside the coupllings can become loose and short out if not soldered or otherwise properly connected. Just a thought.

Lights could work fine without a ground wire, if they are grounded directly to the trailer frame. Now if that ground wire was loose on the light end, it could short out the given circuit, perhaps when you hit a bump going down the road. Then if that same ground wire that is loose, is is contact with the backup lights wire, as soon as you hit reverse, it's gone too.

Check plugs, then lights for wire connections.
 
snowman51789

snowman51789

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Re: trailer running light blowing fuse for revese lights

Last night I checked all the connections and the wires going to the lights except for the center light bar (will do tonight) and everything looked as it should. I also double checked the plug witch is new this year. also all grounds were good

Maybe I should give some other info, yes I do have the selinoid for the brakes, I to have surge disk brakes. My truck came with a flat for so I installed a 7 blade connector and I tapped the wire going to the revers lamps on the truck for the trailer selinoid.
 
Thalasso

Thalasso

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Re: trailer running light blowing fuse for revese lights

If you really want to find the short in short time, ( you might not like this but) take some aluminum foil and wrap around the fuse and when the smoke starts coming out from where ever, pull the fuse and bingo you got it.
 
C

Chip Chester

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Re: trailer running light blowing fuse for revese lights

Based on your late-breaking news, you should determine the current needed to actuate the solenoid, add it to the current needed to operate your vehicle's backup lights, and compare the sum to the value of the fuse in the circuit. (The sum apparently exceeds the fuse value...) The solution is not to increase the fuse value. The solution is to install a relay actuated by the backup lights, but switching a sufficient 12V source to the solenoid.

Determine the solenoid current by research or measurement with a 12V source and an ammeter.
Relay can be a common horn relay, $4 from the auto parts store.
Don't know your available sources of 12V, but it's not going to be one of the other light circuits.

This is all assumes your solenoid is actually working correctly, is properly grounded, has good connections to it, and is not physically stuck.
Start there.

Someone could have been sneaky and put higher-wattage bulbs in your backup lights, too. (Or auxiliary ones, too.) Worth a check.

There will be other solutions offered, of course. But fixing it right once is always the best course of action.

Good luck!
 
snowman51789

snowman51789

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Re: trailer running light blowing fuse for revese lights

But why would the running lights stop working?
 
Bob's Garage

Bob's Garage

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Re: trailer running light blowing fuse for revese lights

Thalasso said:
If you really want to find the short in short time, ( you might not like this but) take some aluminum foil and wrap around the fuse and when the smoke starts coming out from where ever, pull the fuse and bingo you got it.
Click to expand...

Back in my Army days we used to call that "tuning for maximum smoke", LOL. Was used when all else failed!!
 
T_Herrod

T_Herrod

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Re: trailer running light blowing fuse for revese lights

Tuning for max smoke is NEVER a good idea with the trailer and tow vehicle connected. Yes you will find the short but you will also melt the coating off of other wires that are bundled in the same harness. And who knows what kind of damage you could do to the tow vehicle computer circuits. If you want to smoke a hiring harness unhook from the tow vehicle and make an adapter to plug the trailer into. Then use a spare battery or a battery charger that is set on boost (max amps) and hook it to each circuit. When the smoke rolls you have found the problem. Repair it and any other wires that got melted.
 
Boats-A-lots

Boats-A-lots

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Re: trailer running light blowing fuse for revese lights

Thalasso said:
If you really want to find the short in short time, ( you might not like this but) take some aluminum foil and wrap around the fuse and when the smoke starts coming out from where ever, pull the fuse and bingo you got it.
Click to expand...

Uh huh.. I did this 2 weeks ago, and the short was in the light bar under the boat. I mainly use the boat in salt water (the pacific ocean) and 2 of the 3 lights were so corroded the wires were grounding out on the trailer. Couldn't find a stainless steel one to replace it when so I made some mods to the one I had wit stainless.
 
Vegas Naturist

Vegas Naturist

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Vegas Naturist

Vegas Naturist

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Re: trailer running light blowing fuse for revese lights

Thalasso said:
If that works that's pretty cool. Will have to get me one.
Click to expand...

Yes it works, but like any tool, it does have it's limits. I repair school busses for a living, and when you're trying to find a short along 40 feet of bus, it can get aggrevating. The canister acts like a fast resetting breaker, and the meter is basically an inductive amp meter. You start on the power side of the circuit and follow along till you loose amp draw. That'll be where the short is (usually).

John
 
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