Trailer Lights Are Squirrely

[underdrive92]

Okay boys. I have a 2006 F150. I just installed a brand new trailer light kit on my snowmobile trailer.
I have all running lights working left and right. I have right signal. I have Right side only flashing when I hit the hazards. The left side works too but looks more like a power loss from the right side draw. That's it
I have no left signal or brake lights. Infact when I hit the brakes every light on the trailer goes out. Any ideas.

[joezr2]

Almost every weird trailer light condition I've ever troubleshot turned out to be a bad ground. Check all connections and wires for worn insulation. Sled trailers live in a very harsh environment!


I know this sounds dumb but make sure the trailer is actually hooked to the ball of the truck. We found out that the trailer is ground to the truck.

[underdrive92]

What I did was checked the ground on the back of the truck lights and it came out good. The wiring is brand new installed today. It lights up as bright as it should with running lights. and right turn signal. Just the brake thing has me stumped big time.

[Downriver Thunder]

It really does sound like a ground issue. You have a dedicated ground hooked up or are you relying on the hitch to do your grounding?

[underdrive92]

Okay hooked up the trailer lights as diagram showed. I put the trailer on my truck. I hooked in the lights. Seems all power is going to right side. I added an additional ground wire to the back of the lights where they screw on. Now the right side lights are as bright as they can get and the left is not bright at all. It's on but just barely. I disconnect the added ground to the right side doesn't make a diffrence. I disconnect the left and what little light is there goes out. Still no brake lights at all and all lights on trailer go out when I hit the brakes. Maybe my truck is messed up. It is a Ford. *heheh*.

[JasonF]

I know this sounds dumb but did you check to see that you have power at the harness?

[underdrive92]

Everything works but left side signal. Weird I know.

[Spaceman]

It's the ground in the left light for sure. Check it by grounding a wire at a sourse of good ground. next touch that wire to the metal that holds the bulb. It could be a defective light itself.

[paul yarek]

Almost every weird trailer light condition I've ever troubleshot turned out to be a bad ground.[/b]

right on.

first make sure the harness on the truck is fine. then with a wire tester start checking the problem area. i bet it is the ground at the light itself.

[snow prowler]

It defiantly sounds like a bad ground. Is your trailer a tilt? If so check your ground wire from the frame to the main tow bar, where it tilts at. I hope this helps. Snow Prowler.