I could use some advise from anyone on this one. I was coming off of a job in the northeast yesterday and the company that I work for had a trailer that need some wiring done. It was either that or sit in a hotel watching the same BS on TV, so I volunteered to do it. It’s a 16 ft jon boat trailer. Trailer only sees freshwater use. I am no newbie at trailer wiring.
I first hooked the trailer up to a E-250 Series Ford Van, to do some trouble shooting. Not getting power coming out of the Van to the trailer. If figure, bad ground or bad wire, so I chase that down. No Luck. Decide to hook up the F250 Super Duty because I know that there is power coming out of the back of it. Then it dawns on me that I blew the fuses in the van and the truck. Both vehicles in fairly good condition. The trailer was blowing the 20A Maxi Fuses under the hood of both vehicles. Of all the trailers I have rewired, this was the only time I ever blew a fuse. In this case two.
The guy that did the wiring before me, did it correctly. There is no doubt about that. I pulled all of the old wires off of the trailer, no nicks, cuts, bad connections etc…
I did a random google search and found similar problems, and people basically having a problem with the side (running) lights blowing the fuses. So I completely re-wired it, except for the running lights and they worked fine. BUT! I have come to find out that this is a reoccurring problem.
My thoughts are that it is either the running lights OR maybe the EL Cheapo Trailer lights. I have a feeling that the bayonet style bulb might be somehow arcing between posts???
Anybody have a similar experience or some suggestions???
You’ve made a fair assumption in blaming the light fixture. Sounds like you’ve checked the wiring pretty good so that should be ok.
Most of the trailer lights you find on the shelf nowadays are manufactured in China, not good quality at all.(kinda hard to believe)
I had 3 sets of trailer lights over the last few years that shorted in the light socket. All of them were bought from either wallyworld or tractor supply. I thought I would save money and buy the cheaper ones since they were going on a Jonboat trailer, finally bought a set from NAPA that were made in Mexico…couldn’t find any made in USA. These are still going strong.
I would think there must be a 12 volt to ground short somewhere in the wiring or light fixture. To narrow it down you should be able to remove the bulbs from the fixtures and then check at the trailer pigtail that you don’t read any continuity between ground and any of the other 3 pins on the pigtail.
I once ran my trailer light wiring up through my trailer guide posts to the tops. One of the wires shorted out on the short metal post under the PVC pipe. It would be intermittent! Blew the truck fuse a couple of times. I put some new lights on and it was still happening. I was on a long trip so I just put a larger fuse in the truck and blew it too. Put an even larger fuse in to complete the trip. Didn’t work, as the real large fuse finally blew but not before it melted the 7 pin, round trailer plug. Made the last 100 miles with no lights. Only found the short after unbolting and removing the guide post!
quote:Put an even larger fuse in to complete the trip
That’s on the list of things to never do.
Good way to burn your vehicle up.
fuses are not “bad”…if they blow, they blow for a reason.
installing a higher amp fuse does nothing to correct a short circuit.
there is a distinct difference between a “short” and a bad connection. (both can cause headaches though)
As a volunteer fireman, I can’t count the number of vehicle fires I have responded to because someone installed something in their vehicle and either didn’t fuse it at all or fused it incorrectly.
RDW; I knew it was a bad idea at the time, but as it was intermittent and I could get some more miles before dark, I went for it! They call that a Field Expedient, in the military! That means, anything it takes to get the job done and deal with any problems later:wink: It worked, except for that last 50 miles after the plug melted:face_with_head_bandage:
I would think there must be a 12 volt to ground short somewhere in the wiring or light fixture. To narrow it down you should be able to remove the bulbs from the fixtures and then check at the trailer pigtail that you don’t read any continuity between ground and any of the other 3 pins on the pigtail.
'07 198 DLX Carolina Skiff
FS90 Suzuki
I ran into this same problem yesterday. Grounded out the 12v from one of my running lights causing a blown fuse in my truck. Three hours later after rewiring the whole trailer thinking it had a bad ground is when I realized it was the fuse to trailer wiring harness. $3 fuse! Oh well it needed to be rewired anyway. (**() those LED lights look good!
“DaSchwabba”
Tidewater 216 CC
Key West 196 BR -sold
Narcosis, another quick way to see where the short may be is to just power on your headlights and left/right blinker one at a time.
Put a good fuse in the truck and check that the voltages at the truck end are good, You could even use a slightly lower rated fuse if you want to be safe. Make sure all light functions on the truck are off and connect the pigtails. Then try your headlights and blinkers one at a time and see which one blows the fuse.
Easy…Sorry if it sounded like I was doubting your intelligence or belittling what you did. That was definitely not the intent. We’ve all been in that situation where we knew that what we were doing was not really a good idea but we did it anyway because like you said…we had to get the job done.
I once duct taped a milk carton onto the trailer hub to try and keep the rest of the grease from slinging out. Made it to the ramp, but couldn’t make it any farther…Mission accomplished!