Post By: fishman1 Posted: 4/14/2019 5:41:50 PMPoints: 19622
Ok guys, I have a problem. Last fall when we went to Lake Oahe the trailer had a blowout which blew the trailer fender off the trailer. The fender had a marker light on the front and the rear of it. The wire still had the plugs on it. Got a new fender and lights. Hooked the trailer up to the truck and no lights. My name came over with a meter and found with all the lights plugged in the trailer wiring has continuity. Next we checked the plug coming from the truck. No power coming from the truck. Checked some fuses the owners manual listed they were good. Donít know what else to look at.
Man, that kinda sucks, only time my old man's truck had any issues the problem was with the actual plug for the lights, once we replaced that it was fine. That's really strange that no power would be coming from the truck. Although it sounds like the issue might be karma for going to fish Lake Oahe, lol.
You say: No power from the truck.... So, do the brake lights and blinkers work properly on the truck itself? If so, the problem is in the wires connecting to the end plug. Trace the wires back to where they are spliced to the truck wiring. Redo those connections if necessary.
Depending on the truck, you could have several fuses that are in that circuit. Many have specific fuses for trailer lights. Good question above if all the lights on your truck still work. Try the trailer on another truck. If it works, trailer is the problem, if not.. truck is the problem.
Fuses can be blown and still look good. And can have some small connectivity that fools a meter. Try swapping trailer light fuses for a new/ known good fuse. Check both the fuse box under the hood, and in the cab
Reply by: masteroftheloch Posted: Apr. 15, 9:18:14 AM Points: 149
check your ground wire coming form the trailer wire harness to the truck. Check for a splice in the trailer wiring coming from the truck and also from the trailer on the boat. most likely a splice or a loose ground wire.
Reply by: Ajax5240 Posted: Apr. 15, 9:53:06 AM Points: 26183
Trailers will usually find ground through the ball connection to the truck as itís all metal. A bad trailer ground wire more often causes flickering/dim lights. With no power present at the truck trailer plug, the issue is likely on the truck side.
Bill, Iím out of town till Thursday.. if you donít have it fixed by then shoot me an email. I can come take a look at it with you. My son goes to school in Windsor so it would be easy to come by
I don't wanna argue anything here...lol, but take it from a guy who has owned about 8 different boat and trailer rigs... .90 percent of wiring issues on a trailer is due to a faulty ground.... the other times its either a fuse, or a spliced wire.
Beware of the blue squair wire splicers that come with trailer light kits.The little spade inside it cuts into both wires to make a connection,now you got both wires cut in to half their wire bundle,so your wires are open to failure on many different levels.Just learn how to sodier and heat shrink.
Loch.. while it is always good to have a good ground wire in your trailer harness, and certainly a good ground at your trailer plug... connecting a metal trailer to a metal ball that is attached to your truck serves as a pretty good ground. Unless you are one of the weird folks that insists on greasing your ball.. which could add a layer of resistance to the circuit. Ground is ground.
Try taking a multimeter and measuring the resistance (ohms) between trailer frame and truck frame. Itís not much. Not enough to cause a short by any means as that occurs on the positive side, not ground.
Not that it could never cause a problem... but given the fact that Bill has no power at the light plug on his truck certainly points to a blown fuse..
Not in any way to sound like a ďknow it allĒ but automotive electronics is the only thing I have a college degree in... and ASE master certifications in..
I used a multi-meter to determine there was no power coming from the truck side plug. It is factory wiring also. It has two options for plugs, a flat and a round one. Neither has power. I am definitely hoping I donít have to work Thursday so I can utilize Brianís talents. I really appreciate everyoneís comments and help on this! Thatís what I love about this site.
Haha, work Thursday.. I donít land at DIA till like 7p..
Friday or over the weekend I am available. Do some digging around on the fuse blocks in the mean time.
Weíll get you all fixed up! Iíd bet a cold beer or two itís the trailer fuse that got shorted during the blow out. Just gotta check the wiring on the side that had the blowout to make sure the short is fixed so you donít keep blowing fuses.
Compared to cars electrical/computer/sensor systems. Trailers are a cake walk. Especially the ones without brakes.