Trailer Light Problems

[Guest]

What the **** makes it so hard?

I was an electrician for 6 years before becoming an engineer.

There has to be a work around.

For the first time in my life , I failed to replace the lights.

I'm tempted to buy blinking LEDs

[fishinwrench]

It's because the trailer frame serves as the common ground. If you just looped a ground wire and sealed all of your splices it would eliminate 70% of trailer light issues. Some grease on the bulb sockets and coupler plug will eliminate another 20% and unplugging before launching/loading will eliminate the remaining 10%

An active electrical circuit UNDERWATER speeds up corrosion at all the splices and connections x100

[jdmidwest]

But were you a DC electrician?

Run a dedicated ground wire, the white wire in the 4 wire batch, to all of your lights and ground the white wire to the tow vehicle side and it will help. Solder connections as they tend to corrode when wet and use shrink tubes or wrap.

Then you have to check the plug to bulb base continuity to make sure you did not pinch a wire or have a bad plug. I have had bad plugs from the factory.

Switch to leds, they are worth the money. The bulb filaments do not break like the conventional bulbs do from the bumps that trailers take.

[Guest]

okay,

I didn't think about a dedicated ground wire or soldering, but that makes sense.

I'm trying to sell this rig, so probably wont get LED's unless these lights don't work.

Thanks guys, I will check back later on with results

[Seth]

Do you not have running or brake lights on either side at all on the boat trailer? If not, I would have to think something is wrong at the plug on the truck or boat. If your grounds are good, you should have something lighting up since you have yellow and green for your turn signals and a common brown wire for running lights on each side. Do other trailers work fine on that same vehicle when plugged in?

[Guest]

Do you not have running or brake lights on either side at all on the boat trailer? If not, I would have to think something is wrong at the plug on the truck or boat. If your grounds are good, you should have something lighting up since you have yellow and green for your turn signals and a common brown wire for running lights on each side. Do other trailers work fine on that same vehicle when plugged in?

Nothing,

all the lights wiring & harness are brand new.

The truck tested good.

So its got to be a grounding problem.

[Seth]

Have you hooked it up to another vehicle or even straight to a battery? I keep a spare plug for the vehicle side around so that I can test the lights directly on a battery. Touch the white wire to the negative side of a battery and the yellow, green and brown to the positive side of the battery. That will at least take the vehicle out of the equation and let you know if the problem is with the trailer or the truck. Wiring a trailer is simple so I can't imagine that being the issue if you just installed a new harness. Even with a bad ground, you should get something to light up if it's getting power to the trailer.

I would get a tester and ground it to the truck frame and then check the green, yellow and brown for juice. If that doesn't work, then check the truck side right before the plug. If you got juice at the truck then you have a bad connection at the plug.

[Wayne SW/MO]

Basically in a nutshell the trailer frame is the grounding conductor to the truck which in turn is the grounding conductor to the battery. It has to be complete.

If you go to Home depot, Lowe's, or an electrical supply house get some anti corrosion paste for aluminum wire, it works on corrosion, not just AL wire, and use it everywhere you make a connection. On the trailer you can use a washer under the bolt and the paste under the washer, then cover it with silicone. You should never have another problem. Do this anywhere you had a bolt or screw making a connection.

[Guest]

Basically in a nutshell the trailer frame is the grounding conductor to the truck which in turn is the grounding conductor to the battery. It has to be complete.

If you go to Home depot, Lowe's, or an electrical supply house get some anti corrosion paste for aluminum wire, it works on corrosion, not just AL wire, and use it everywhere you make a connection. On the trailer you can use a washer under the bolt and the paste under the washer, then cover it with silicone. You should never have another problem. Do this anywhere you had a bolt or screw making a connection.

I thought about the paste yesterday, so I might try that.

The grounding bolt, washer & clip are very rusty.

Most of the threads are rusted to where its hard to tighten down on the bolt.

I will replace it first, then try the paste on the new bolt.

[Guest]

Have you hooked it up to another vehicle or even straight to a battery? I keep a spare plug for the vehicle side around so that I can test the lights directly on a battery. Touch the white wire to the negative side of a battery and the yellow, green and brown to the positive side of the battery. That will at least take the vehicle out of the equation and let you know if the problem is with the trailer or the truck. Wiring a trailer is simple so I can't imagine that being the issue if you just installed a new harness. Even with a bad ground, you should get something to light up if it's getting power to the trailer.

I would get a tester and ground it to the truck frame and then check the green, yellow and brown for juice. If that doesn't work, then check the truck side right before the plug. If you got juice at the truck then you have a bad connection at the plug.

Ive got a 4 flat plug-in tester that works on my truck.

3 other vehicles have been hooked up to the trailer & nothing.

very frustrating