By Roger Garland
Keeping those &%$@ &%#@ Trailer lights working can be a real pain. Every time you want to go somewhere the lights seem to act up. This article is an attempt to tell you how I have managed to keep mine working.
The problem is particularly bad if the trailer gets dunked in salt water. When the parts rust the ground is lost and the lights act very strange.
The solution to light problems is to keep the corrosion out of the wires and the lights.Here is what I do. I start with a new set of lights. I disassemble them so all metal parts are separate. Then I coat all the metal parts with a grease I have found will not wash out. I have tried oil chassis grease and others but I have found they all disappear and the parts rust. The grease I use is a fibrated wheel bearing grease. I have used this on farm equipment and after 8 years the bolts are easy to undo. It is probably OK to use an antiseaze compound but I have not tried it.
It is very important to remove the mounting bolts from the light as corrosion between the bolts and the other parts will destroy the ground. Also coat the bulbs and the sockets. The mounting bolts and the nuts should also be greased. The side marker lights get the same treatment.
After the lights are mounted I install the wiring. The wiring needs to be done with connections that are water proof. Don't use the crimp connections that will let the water reach the wires. I use electricians wire nuts. The two wires are stripped and the wire nut screwed on. The wire nut is then filled with silicone to keep the water out. If I want to undo the connection for some reason the silicone will allow the joint to be undone. Other methods are to use crimp connections and shrink tubing or liquid electrical tape.
I also grease the connection of the ground wire to the frame and the 4 prong connector.
When you buy your light kit you want to get one with a split harness. This means that two wires go down each side of the trailer. The 4 prong plug will have 5 wires attached to it.
The white wire is the ground and is attached to the trailer frame near the front. There will be two brown wires and one goes down each side of the trailer. These wires will have a connection at the side marker lights near the front of the fenders. They will then continue to the tail lights. The light bar in the center is also connected to the brown wire.
The yellow wire at the plug is for the left stoplight and the green is for the right stoplight. One of the wires out of the taillights will be brown and the other wire will not match the color of the harness wire.
If you connect your lights as described here you will probably never have a failure of the lights caused by the wiring. When replacing burned out bulbs be sure to grease the new bulbs. One thing to know is that if the taillights work and then they go out when you step on the brakes the trouble is in the ground circuit. If the lights are already rusty it is worth buying new lights.