bknudsen30

hello everyone. i have a 2001 f150 with the tow package. i just got a boat and trailer. when i turn on the driving lights the lights light up like normal until i press the brakes, then they all go out. then when i put on the turn signals, the hazards come on. i'm really lost looking for any help. thanks

tmajor

What lights light up "like normal"? Do you have side marker lights or just the tail lights? If just tails lights, I'm guessing, the trailer wires are reversed and really what you are seeing is "brake/stop lights" instead of parking/tail lights.

bknudsen30

i have side markers. i have checked all the wires none seem to be reversed but i could be missing something

tmajor

Make sure the ground is there and goes through to the trailer. Disconnect the trailer and check the truck plug for pulsating voltage on the correct pins with T/S on.

bknudsen30

where is a good place for the ground

tmajor

The truck plug has a ground wire in it. Which plug are you using 4 way or 7 way? The truck plug could have the ground wire attached to the frame, same with trailer (same place the trailer lights are grounded). Sometimes, there isn't a ground wire and the ball hitch is depended on for ground (usually intermittent). You could take a battery jumper cable and run from good ground (bare metal) on truck to frame of trailer, for a test.

bknudsen30

its the 4 plug. ill try the jumper cables. thanks for your help.

tmajor

If the jumper cable solves the problem and the White ground wires are present, both, the truck and trailer, it could just be poor connections in the plugs. ... especially, if one side or the other hasn't been used lately.

Abn150

Corrosion (poor connection) and ground are common problems with boat trailers, would start there.

RedOne

Do you have another trailer to try with your truck or another truck to try with your trailer? This will tell you which vehicle to work on...just a thought.

I would guess it is corrosion or ground issue also.