Trailer Issues -- no running lights?
10-16-2012, 10:18 AM
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Trailer Issues -- no running lights?
I hate trailer wiring!
I had two perfectly good working trailer lights on my boat trailer. A rock kicked up and busted one to pieces. In the interest of matching, I replaced both at the same time, and wired them up simply. Two wires to each, matched colors, done, just like the old ones. With the new ones on there, the brakes, turns, and hazards work great, they won't light up with the truck headlights and taillights. I have been told its a ground issue but the ground to the trailer is solid, metal on metal. For good measure, I disconnected it and reconnected it with some contact grease. Also, the trailer lights are grounded with the attaching nuts on the frame, and there is no debris or paint in the way to prevent that connection. Also, I cleaned out the plugs and added contact grease to ensure good connection.
Why the hell would no-modification, wire to wire, light to light replacement cause my running lights to not work on the trailer?
FYI This is a 4 plug connector on a 2000 F150 XLT 4x4 with the factory tow package, connecting to a 4 plug trailer harness on a 14 ft v bottom boat trailer.
I had two perfectly good working trailer lights on my boat trailer. A rock kicked up and busted one to pieces. In the interest of matching, I replaced both at the same time, and wired them up simply. Two wires to each, matched colors, done, just like the old ones. With the new ones on there, the brakes, turns, and hazards work great, they won't light up with the truck headlights and taillights. I have been told its a ground issue but the ground to the trailer is solid, metal on metal. For good measure, I disconnected it and reconnected it with some contact grease. Also, the trailer lights are grounded with the attaching nuts on the frame, and there is no debris or paint in the way to prevent that connection. Also, I cleaned out the plugs and added contact grease to ensure good connection.
Why the hell would no-modification, wire to wire, light to light replacement cause my running lights to not work on the trailer?
FYI This is a 4 plug connector on a 2000 F150 XLT 4x4 with the factory tow package, connecting to a 4 plug trailer harness on a 14 ft v bottom boat trailer.
10-18-2012, 12:16 AM
#2
Senior Member
It's likely a blown fuse that went when the light was broken causing a short in the circuit.
It's an easy check and fix. Start by checking to see if you have a taillight/ marker light signal at your plug. If you don't, the fuse is likely blown. Of you do, then we know you are getting signal to the trailer from the truck. Next check and see if you have signal to this circuit at the wires going into the light itself. If so, you likely have a grounding issue with the light. If not, you likely have issues between the front of the trailer and the back.
I'm still leaning towards not getting signal from the truck at all.
EDIT....I make my living working on stuff like this. If you don't have any luck I'd be more than happy to give you my number at the shop to help talk you through this.
Buck
It's an easy check and fix. Start by checking to see if you have a taillight/ marker light signal at your plug. If you don't, the fuse is likely blown. Of you do, then we know you are getting signal to the trailer from the truck. Next check and see if you have signal to this circuit at the wires going into the light itself. If so, you likely have a grounding issue with the light. If not, you likely have issues between the front of the trailer and the back.
I'm still leaning towards not getting signal from the truck at all.
EDIT....I make my living working on stuff like this. If you don't have any luck I'd be more than happy to give you my number at the shop to help talk you through this.
Buck
10-18-2012, 10:22 AM
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I solved it! There is a 4 foot extension from the trailer wiring to the truck's trailer hookup since the trailer has a long neck. I bought a new extension, and found at Walmart they have testers you can plug to a 4 plug receiver which will light when electricity is coming through. I plugged that in, and got turns and hazards and brake no problem, but the brown wire for running lights would get it for a little then lose it. Turns out there is something about the extension that doesn't carry the electrical connection to the trailer, and something about the truck's wiring receiver that means I have to tilt it just so when I plug the new extension into the truck's 4 plug receiver. Tilted just so, it will maintain contact with all four plugs and all the lights work. I can zip tie it so it maintains a clean connection consistently and that solves the problem. Also I changed all the bulbs on the trailer, which can't hurt either.