Boat Trailer Fuse Keeps Blowing

[EZM]

On my 2010 GMC sierra, there is a 15amp "TRLR PARK" (night time running lights and marker lamps for boat trailer) that keeps blowing.

I'm running a 7 pin to flat four converter (not sure if that matters in this case).

I have checked the wiring, found no obvious issues, at any accessable junction point. The bulk of the wiring runs inside the trailer tubing.

Neverless I insulated any "suspect" pinch points, re-wired and installed new LED tail lamps, put n rubber insulators and the moment i turn on the running lights she pops again!!!!.

Turn signals, brake lights, hazards uneffected (they work fine and have seperate fuses in my GMC).

I don't want to have to re-wire my entire trailer (a 2009 trailer) if i dont need to.

Any ideas before I undertake the giant pain the @$$ of re-wiring the entire trailer???

Anyone had this issue? any thoughts???

Thanks in advance.

[pikergolf]

Are you submersing the lights, if so try unplugging first.

[EZM]

I always unplug them before a dip but, in this case, there is no need to submerse lights - fuse blows right away in my garage. I wish i could make it more than 10 seconds before she blows.

[bellr77]

Any chance a small side sealed marker light has was water in it still from a leak at the top?

I would also suggest hooking it up to another vehicle to at least eliminate the chance its in the truck cause it could be the plug on the truck itself.

[EZM]

Any chance a small side sealed marker light has was water in it still from a leak at the top?

I would also suggest hooking it up to another vehicle to at least eliminate the chance its in the truck cause it could be the plug on the truck itself.

Good thoughts - the lights are dry thats not the issue.

I do like the idea of hooking it up to another vehicle to eliminate the variable (being my truck). That is a great idea, thanks.

I will ask trophypikehunter to bring his rig over. He smashed my tail light last weekend and caught more fish than me so it's the least he could do.

[Rainbow]

I just had the same problem with my boat trailer.The company that did the wiring gave me a diagram of their installed wiring.I wired my trailer to their specks but as soon as I hooked up it kept blowing fuses.They told me that I had a dead short in my trailer.
I checked the power coming out of the SUV.It was different than what THEIR diagram said.Rewired my trailer to correspond with the power coming out of the truck.Works fine now.THEY had the ground wire and running lights/brake lights mixed up.
Phoned them up,told them they had screwed up.I didn't even get a sorry from them.That is the last time I ever get any hitches or wiring done with this company.
If anyone wants the name of the company to avoid this problem,send me a PM.
Thanks
Rainbow

[ice]

Similar issue on the fifth wheel, while it dosent blow right away after the second or third trip it's gone.

[ESOXangler]

Its behaving exactly like a dead short. Check all your terminations and areas where the wire could potentially ground out as well. Good luck!!

[TROLLER]

Exact same thing was happening to me with my EZ Loader. I actually kept spare fuses just for that.

anyway,, next time the boat is off take a close look especially around your fender marker light, bet ya a buck there is an exposed wire. I found mine, taped it over and that was the end of blowing fuses on my truck.

[Bigwoodsman]

Exact same thing was happening to me with my EZ Loader. I actually kept spare fuses just for that.

anyway,, next time the boat is off take a close look especially around your fender marker light, bet ya a buck there is an exposed wire. I found mine, taped it over and that was the end of blowing fuses on my truck.

I had ths same problem several years ago, on a pickup I had. I had the same problem with different trailers, so that made it easy to determine that the problem was in my truck. The guys who put in my 5th wheel hitch and wiring used butt connectors, instead of solder and shrinktube. Taped everything up, after a couple of season the salt and grime caused a short. Had it fixed properly and never anymore trouble.

BW

[Rascal4now]

I had similar problems. I paid $450 to have my camper wired to truck and 12v system in camper. Never did work right. I kept blowing fuse after fuse as soon as I turned on my lights.Affected for running lights/tail lights and panel lights.
A wise person i know suggested i buy a small diode thing, hook two wires to it and use it as a fuse. It lasts longer to allow you to check your bulbs and connections. It has a switch in it that heats up and will just shut off and on. Works great. Still working on my problem but may help you find yours without blowing fuses.
I should add that mine is a 96 sierra

[Rick.]

Princess Auto sells a 4 wire flat connection tester for about 3 -4 bucks. That will tell you if your truck is right/wrong. Look over your connections for anything obvious. You could hook up a battery direct to your three power wires one at a time and see which one starts to burn (dead short). If it isn't obvious your probably quicker to re-wire the trailer. and be confident in your system. Best of luck. Rick.

[Kokanee9]

Princess Auto sells a 4 wire flat connection tester for about 3 -4 bucks. That will tell you if your truck is right/wrong. Look over your connections for anything obvious. You could hook up a battery direct to your three power wires one at a time and see which one starts to burn (dead short). If it isn't obvious your probably quicker to re-wire the trailer. and be confident in your system. Best of luck. Rick.


That's a great suggestion. I didn't know they sold something like that.

[Big Schnizz]

On my 2010 GMC sierra, there is a 15amp "TRLR PARK" (night time running lights and marker lamps for boat trailer) that keeps blowing.

I'm running a 7 pin to flat four converter (not sure if that matters in this case).

I have checked the wiring, found no obvious issues, at any accessable junction point. The bulk of the wiring runs inside the trailer tubing.

Neverless I insulated any "suspect" pinch points, re-wired and installed new LED tail lamps, put n rubber insulators and the moment i turn on the running lights she pops again!!!!.

Turn signals, brake lights, hazards uneffected (they work fine and have seperate fuses in my GMC).

I don't want to have to re-wire my entire trailer (a 2009 trailer) if i dont need to.

Any ideas before I undertake the giant pain the @$$ of re-wiring the entire trailer???

Anyone had this issue? any thoughts???

Thanks in advance.

Did you ever resolve this? I think I have the same issue.

[stickflicker]

Check the resistance of your circuits to ground with a multimeter to find a short. Low resistance shows a short, fuses burn out from high current as a direct result of low resistance...or too much power...:sign0111:

[EZM]

Did you ever resolve this? I think I have the same issue.

Issue is resolved ............. sold that boat and bought a new one this spring ...lol.

However, in order to prepare it for sale ( I like to sell my stuff in proper working condition with no surprises ) I re-wired the trailer completely (wire, marker and tail lights) and the issue resolved itself - I guess the OEM wiring must have gone wonky at some point. Cost me $60 and an hour and 15 minutes.

The boat was a 2010 Smokercraft with factory trailer.

[JohninAB]

I had this exact issue last fall on my trailer. What it was was a wire coming out of the frame to the marker light on the wheel fender had wore thru and was grounding out on the frame. Quick snip, solder and shrink tube and not an issue since.

[Lefty-Canuck]

If you have a voltmeter ohm out or check your hot to chassis ground....should be no continuity between the two.

LC

[TROLLER]

On my 2010 GMC sierra, there is a 15amp "TRLR PARK" (night time running lights and marker lamps for boat trailer) that keeps blowing.

I'm running a 7 pin to flat four converter (not sure if that matters in this case).

I have checked the wiring, found no obvious issues, at any accessable junction point. The bulk of the wiring runs inside the trailer tubing.

Neverless I insulated any "suspect" pinch points, re-wired and installed new LED tail lamps, put n rubber insulators and the moment i turn on the running lights she pops again!!!!.

Turn signals, brake lights, hazards uneffected (they work fine and have seperate fuses in my GMC).

I don't want to have to re-wire my entire trailer (a 2009 trailer) if i dont need to.

Any ideas before I undertake the giant pain the @$$ of re-wiring the entire trailer???

Anyone had this issue? any thoughts???

Thanks in advance.

Had the same problem. Somewhere you have an exposed wire. It has rubbed against the trailer and now a small wear point or cut has arrived.

Check the wires closely especially around the fenders when you have the boat off next time out. If you find it simply tape it off.

[The Reel Deal]

It's also possible that there too many bulbs on the running light circuit or if you have upgraded to LED bulbs. This causes a drop in resistance and an increase in amps being able to pop the fuse.

[Big Schnizz]

It's also possible that there too many bulbs on the running light circuit or if you have upgraded to LED bulbs. This causes a drop in resistance and an increase in amps being able to pop the fuse.

I will take a look at the wiring to see if there is anything I can see. If this is the case though with the increase in amps, could it possibly be fixed by upping the fuse from 15 amps to 20?

[The Reel Deal]

Increasing the fuse size is never recommended. But if you did, you have to rule out any shorts in the wiring, ( can cause fires). Adding a resistor into the circuit is the right way, specialty electronics stores stock resistors ( B&E Electronics in Calgary)

[The Reel Deal]

If anyone has electrical issues you can pm me and I'll get back to you with tips

[Peter Gill]

If you have a multimeter, you could check the amperage flowing across the fuse points. I wouldn't put in a larger fuse without upgrading the wiring, you might turn a wire into a fuse and it won't be pretty.
Have you checked the contacts and wiring right at the fuse block? I've seen those get corroded and short to ground, which certainly seems to be your issue.
Can also check continuity (resistance) from the fuse cold side to the plug (maybe check the 7-pin first, then attach the 4-pin & check again?), if that's good then power that circuit and see if you've a short in the wire.

[Big Schnizz]

My problem in my GMC was simply the fuse. Towing something else must have blown it in the past because I changed out the fuse and the running lights now work.