trailer lights shorting - any advice?

[pjwalleye1]

Hoping someone smarter than me can provide some assistance. The trailer lights for my 1998 Alumacraft work fine during the day, but once I turn the nighttime running lights of the vehicle on, the fuse on the vehicle for the lights shorts out, thus rendering my vehicle taillights and boat trailer lights dead. I've checked the groundwire and it appears ok, although perhaps not good enough to handle the extra current burden when the running lights are turned on... Any advice out there to diagnose and fix this problem? Thanks much!

[chunkytrout]

With an ohmeter, touch one lead to chasis on the trailer and the other lead to your brown trailer wire. If there's continuity with zero resistance, you have a direct short. I doubt it. You should get an ohm reading of the running light circuit. I'm guessing the problem is on the truck side. Follow the brown (running light circuit ) from the plug back to it's source and check it carefully for nicks or bare copper. Alot of times, it's a crappy install problem. I also highly doubt your overloading the circuit unless you have that trailer lit up like a xmas tree, besides it used to work right?

chunky

[pjwalleye1]

Hoping someone smarter than me can provide some assistance. The trailer lights for my 1998 Alumacraft work fine during the day, but once I turn the nighttime running lights of the vehicle on, the fuse on the vehicle for the lights shorts out, thus rendering my vehicle taillights and boat trailer lights dead. I've checked the groundwire and it appears ok, although perhaps not good enough to handle the extra current burden when the running lights are turned on... Any advice out there to diagnose and fix this problem? Thanks much!

[walleyewizard]

I had the same problem with my GM pick-up, day-time lights worked fine, but night-time lights would blow fuses. After pulling my hair out trying to find the short, I just re-wired the trailer and haven't had a problem since. Simple fix for a frustrating problem. Now I just have to worry about sun-burning my bald head.

[Mankato-Ice-Man]

Trailers are so much fun. I just rewired mine. Have tail lights. Have both blinkers. NO BREAK LIGHTS. Ugggg. I am almost thinking its a problem with the truck and not the trailer.

They have a variety of trailer wire kits at WalMart for well under 30.00. Check them out if that is what you decide to do.
Good luck.

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Give a man a fish, he will eat for a day; Teach a man to fish, and he will steal all your best spots!

[Guest]

I'm not an expert at wiring, but I do know if you have both signals, you should have brake lights. Do you have the 4 wire system? One wire is the ground, one is the tail and the other 2 are signals/brake. Have you tried testing the plug on the Truck end, that will tell you if the Truck is the problem. Just an idea, hope you solve it.

[pjwalleye1]

Thanks everyone for your input - it was indeed the ground connection on the truck - I didn't want to believe it, which is why I spent so much time on the trailer. Darn thing was corroded and rusted pretty bad! Good luck all.

[Gissert]

If your truck does not blow the fuse when the trailer is not connected, the problem should be in the trailer side of things.

There is probably a dead short to ground in one of the light assemblies on the trailer.

The gentleman who suggested the trailer rewire option is right on the money. Factory wiring and light assemblies are usually not top of the line. Aftermarket is the way to go.

If you dont want to go that route right now, try this: Open up and remove EVERY light bulb from the trailer. Hook the trailer up to the hitch and connect the harness up to your truck. Turn on your running lights, and see if the truck fuse blows. If it does, the short is probably between the hitch harness and the first light assembly. If the fuse does blow, put the bulbs back in one by one until you blow the fuse. When the fuse blows, look very closely at that light socket/assembly.

Good Luck.

[92python]

I was having the same problems so I brought my boat in for a complete rewire from the plug back to the lights. The problem resurfaced after the re-wire and I thought I was going crazy. After bringing the boat in and having the marina check the check the connections again one of the guys told me that one of the wires in the trailer was original. That pis@ed me off and the guys at the marina told me they would rewire the thing again and finally do as I asked for "free". Everything works fine now.

I should have done the re-wiring myself but I was having boat work done at the time.

I would just buy what you need and rewire it yourself. Tie the new wores onto the old wires and use them to pull the wires through the trailer if possible. You will probably find some exposed wire somewhere on the old wires.