Trailer lights
 

Noticed yesterday when applying the brakes that all the trailer lights light up. Got out and checked them and they all appear to be working. One thing I did notice is the right side brake light is not as bright as the left. So I swapped the two and same thing. The right side turn signal will not work with either lamp. Any suggestions?

Re: Trailer lights
 

Get LED's.... :) Best money I ever spent, no more headaches...

Re: Trailer lights
 

Bad ground?

Re: Trailer lights
 

Where should all the grounds be located? It's just the secondary light thats not lighting up.....when the parking lights are on...everythings fine....when you hit the brakes the right side lamp does not brighten...only the left. It's not the lamp either because if I swap lamps same thing happens.

Re: Trailer lights
 

Sounds like a bad ground. I just re-wired my trailer. I have a 7 way connector on my truck and one prong is a ground. I ran that wire, from the trailer side connector, to the brakes and then spiced it and screwed it in the frame for a ground by the tongue. Your brake lights should be grounded to the frame. Trailer connections are easily corroded from dunking in the water and are a PITA to diagnose. I always cover my connections with electrical grease. Hope this helps.

Re: Trailer lights
 

I would guess it's a bad ground also, you can ground them at every light if you have too but that's a little excessive usually one ground on the trailer is enough. Most that i have seen are grounded right at the front but if your just having problems with one light the wire coming out of the light may be broken.

Re: Trailer lights
 

Get LED's but check all your grounds.

Freaking trailer electrics..... the voodoo world of boating!

Kick, yank, spray, swear, sweat, splice, tape and sometimes it works for five minutes

Re: Trailer lights
 

actually this might pin point it more.....when I apply the brakes, all the lights light up. Sounds like a bad ground....but how the heck do I fix it?

Re: Trailer lights
 

If your trailer is like mine, they couldn't all light up with a bad ground.

Re: Trailer lights
 

Sounds like a bad ground - mine did the same thing this past spring when I bought a new ball mount. Alot of the trailer mfg just hook the ground wire to the trailer and let the ground go thru the trailer ball/receiver to the truck frame. New ball mount had no bare surfaces (it was powdercoated), so there was no good "path" for ground and the trailer lights did all kinds of goofy things. If you look at the wiring connector on the trailer, I'll bet you that there is no wire to the ground terminal, or if there is a wire, it is probably not connected to anything. My ground wire from the connector was just hanging inside the plastic loom, connected to nothing - the trailer co was depending on ground thru the trailer frame thru the trailer ball into the truck frame (and ground). I connected the ground wire from the connector (trailer side) to one of the bolts on the trailer frame giving me a dedicated ground to the truck and all my lighting problems went away!

Re: Trailer lights
 

Noticed the trailer grounds just under the toungue....do I just run another wire and test it? Not really sure how to do this.

Re: Trailer lights
 

Electric + water= :eek:

Re: Trailer lights
 

Got jumper cables? Clamp one to the trailer and to the bumper or something else metal and clean and try again :)

Re: Trailer lights
 

Check the numbers on the bulb. A higher number will make that bulb brighter.

Re: Trailer lights
 

I don't think it's the bulb....if I swap lamps, each does the same thing.....no turn or brake signal on right side. When I apply the brakes, every light on the trailer lights up. All the lights work....it's just when I apply the brakes the right side will not light up.....I thought it was the bulb so I swapped lamps and same thing happens.

Re: Trailer lights
 

97bosshammer, what type of connector do you have coming off of the trailer? 4-wire flat connector? If so the white wire coming out of the connector needs to be attached to the trailer. Then if the wires to the lights are color coded correctly make sure all of the white wires are attached and have a good connection, they can be attached to the trailer anywhere as lond as you have a good clean connection or they can all be daisy chained togeather and attached to the trailer in one location or directly to the lead that is coming out of the connector.

Re: Trailer lights
 

Sounds to me like theres a pinch in the line shorting out the brown and green wires somewhere (right side)......try looking at the route of the wires through the trailer and see if anything is pinching the line or may have cut through and is shorting them out.

Re: Trailer lights
 

All the grounds appear to be connected good.....wiring looks like it's good too.....geez what a mess.

Re: Trailer lights
 

Ok I think I'm getting somewhere now.

Currently all lights work......but here's the prob. The Drivers side tail light is on constantly.....as in bright. The passenger side remains dim but when you apply the brakes it will not brighten. It's not the bulbs, they work. For some reason the left side is bright and right side is dim. Left side blinker works, right does not.

Could this maybe be a bad 4 wire flat connector?

Re: Trailer lights
 

ok here's what I found out using the test light.

Right side.......parking lights on.....2 out of 3 sockets are hot (showing test light)

Left side.....parking lights on......1 out of 3 sockets are hot (showing test light)

What could my problem be?

Re: Trailer lights
 

Ok ran some tests before my test light blew up.....

All test good from vehicle

Each of the lights has 3 male ends which plug into the light

Right side....2 studs are hot
Left side....1 stud is hot.

All in all I believe only 1 stud should be hot on each end.....then when the brakes are applied I should have 2 studs hot on each end....am I correct?

And if I only have 1 hot when brakes are applied then I've got a wiring problem between the 2 I'm assuming.

Re: Trailer lights
 

1 wire is parking light, 1 wire is brake/blinker, 1 wire is ground. Disconnect all your lights. To test wires, turn your key on. Turn the parking lights on. Brown wire is parking lights,although yours may be diff. It depends who wired the trailer. Yellow is one side blinker, green is the other side. Turn blinker on and test wires before they connect to light. Do the same to the other side. When using the test light make sure the alligater clip has good contact to the trailer. Touch the wires with the other end and see what lights up. Ittook me a long time to figure mine out. I don't understand electricity to well, along with many other things! Hope this helps.

Re: Trailer lights
 

If you have a low curent battery charger and get tired of running to the truck all the time ground it to the trailer and connect the hot to the wire you want to test. in the plug end witht the three studs one is ground, one is marker, one is tail. If both are lit up besides the ground check where they are connected at to the pigttail by the light. Also are your wires ran in the frame of the trailer or exposed on the under side? if exposed check where they weave in and out of the wire holders for a rubbed spot in the marker and turn wire colors. are the housings sealed lights where you throw the whole unit out or is it a bulb style. If a sealed then its in the wiring, bulb type check for corosion in the taillight housing where the bulb sits at. Also check to make sure that at the light the ground is good, it might look like it, but take it out and wire brush that spot and reinstall again.

Re: Trailer lights
 

Your right....I have brown yellow and green.....going to try a few more tests now and try to find out whats up.

Re: Trailer lights
 

Ok here's the prob now.

parking lights all work

apply brakes and the right side will not brighten, nor will the blinker work, right side.

Left side is all fine.

Re: Trailer lights
 

problem solved.

Disconnected the light and took it up to the housing and checked it. Apparently the Green wire is bad or something. I'm going to run a whole new wire down the trailer and that'll solve the problem (I hope)

Thanks for the help everyone and especially Forumla, I know I had you scratching your head a time or two :)

Re: Trailer lights
 

Thats the problem with dunking trailers, everything gets wet. Some people test lights by poking the test light into the wire to make contact. This leaves pinholes in the wire to allow water to get in and corrode the wire. It can happen anywhere in the wire and is drives you crazy trying to find the problem!

Re: Trailer lights
 

Yeah that might be my next prob....I've cut the wires and put electrical tape back on them. I'm pretty sure water will get in there so I might have to come up with a better solution.