Yes again another trailer brake light problem
 

I have an 2004 1/2 ton 4x4 with towing package. My problem is my trailer brake lights dont work. All other lights work on trailer. They use to work , then 1 went out and still wont work. Then the other day the other went out. I have look and tried everything they suggest. I put in LED tail lights and after that it went all down hill. I have changed the lights to news regular tail lights. All lights on the truck work no problem. I have tested the trailer brake wire form truck with test light, the light was very dim, but brakes worked. When i step on the brakes and look for a hot wire, i dont find any. Turn-park and markers light alll work. I use a 7 prong trailer plug. Have changed plug. Checked ground all grounds. I am at a loss. If anyone has some other ideas please share.
Thank you

By what it sounds like is that you have power coming from your Truck?
Just to cover bases check your wires inside of the plug and connector to
make sure you do not have corrosion, or a strand of wire that is touching
another post.

What you are describing sounds similar to a problem that I had on a Prowler
travel trailer. First one brake light would go out then another.

How I solved the problem was to solder the wires to the light fixture where
they clipped on, for the most part this solved the problem. Every once in a while
I would still have to clean where the bulb made contact with the prongs in the
fixture.

Once you clean up your connecting points put a little dialectic grease on the
contact points.

I also put a little dialectic grease on the brake light bulbs on the truck.
When you pull your break light bulbs you will most likely notice burn spots
on the small wires. The small wires on the bulbs want to arc in the fixture
the dialectic grease will stop this.

Hoped this helped

jvp

Yes i have power from truck plug for every light , but not brake lights. Turn (left and right) hazzards-running lights also power to electic brake. When i push brake pedel down and check all connection all i get is my electric brake. My lights are the sealed oval type. I have changed all contact point on the 3 wire plugs on the tail lights. I am at a lost as to what it is.

Check the trailer light fuse and the brake light fuse under the hood

Yes I have checked all fuses and they are all good. Did some more checking and still no brake lights. This is my work trailer 16' enclosed. I have been putting on my park lights everytime i need to stop--lol just so ppl see some sort of lights go on.

do the turn and 4way lights work?....if so you have a wiring problem....I would start with the truck and make sure you have the "signal" coming out of the truck harness......if that is all good then I would use a battery and some jumpers and check each wire on the trailer at the lights.....if the turn and 4ways work you deffinatly have a wiring problem because the brake light filament is the same as the turn and 4way filament. I had to do this on my trailer once and found a rubbed wire.

I have a 04 silverado with the same problem, left and right turn signals work on my trailer, but only the left brake light works. I traced back to the fuse panel inside the door, the fuse is good, but I do not get 12 volts at the fuse when I step on the brake. I think I need a wiring diagram to proceed any farther.

The yellow and green terminals in the plug are for signals and brake lights.

Ensure that the truck lights all work properly.

If signal lights work and the brake lights on the trailer do not, you need to trace the (yellow and green) wiring back from the plug and see where the corrosion/loose connection/broken wire is.

Do the brake lights on the truck work?

Does anyone know where to find a electrical schematic for a the 04 silverado. I have traced back as far as the fuse panel, the fuse is good, but there is now power to the fuse when the brake is applied