Trying to fix trailer lights - HELP

[AJMBLAZER]

I suck at electrical so I want to get that out of the way first. Use small words and talk slowly.

Trying to fix the lights on the 12’ twin axle trailer my wife inherited.

The running lights won’t work and on the right side (passenger) nothing works.
Driver’s side has turn and brake only.

I redid the connectors going to the passenger side to see if that brought the blinker back at least. Nada.
Cleaned up the ground on the tongue. Nada.
Swapped bulbs around.
Nada.

Looking for ideas. It’s a 7 pin plug and the electric trailer brakes work fine. Wiring runs up inside of the driver’s side frame rail to the driver’s side light and then over to the passenger side light.

 

[sweetk30]

late model vehicles ....... have extra fuses under hood ....... for trailer lights ......... check them

after this it sucks . start from the front and work back .

 

[Wes Harden]

is it 7 round or 7 flat ? test the truck 1st. make sure you match hopefully the trailer uses standard color scheme wire.
I like this one best all should be done this way

 

[sweetk30]

Round 7 is ment for BIG truck stuff . Our little stuff should be flat 7 only .

 

[shady]

7 pin round is all I use.

And, buy a new wiring kit for it and start over is my usual go to lol.
But redo the grounds at each light is the best place for you to start.
Take the ground off, clean the ground wire end, and trailer where it connects, to bare metal, then reconnect.

 

[ktmoutfront]

7 blade is non commercial. Both plugs are round.

Like they said, check the tow vehicle plug first. Use this. https://www.amazon.com/Oyviny-Trail...hvlocphy=&hvtargid=pla-4584345032335415&psc=1

If that is working, plug the trailer in. Apply all of the lights. Check the tow vehicle again. If a short exists, it should have blown a fuse.

I have found it is best, some times, to just replace all of the trailer wire.

Continuity test each wire on the trailer to the frame to check for shorts.
The brake wire will have continuity. That is ok.

Pull the trailer pigtail plug apart and see if everything is connected.

Check the bulb sockets to see if they are clean.

 

[AJMBLAZER]

Thanks guys. About to get back at it but I did dink with it more last night.
It is a round 7 connector. I think the big 3 put them on all trucks now as well as a flat 4.

Hooked the wife’s Yukon up and got the exact same results. Interestingly, aside from being a hell of a nice ride, it’s also a trailer wiring check tool. It immediately started flashing “check trailer running light wiring” and “check trailer passenger side turn signal”.

Starting to be of the, “just replace the whole mess” train of thought.

 

[HankScorpio]

Seems that most of my trailer issues end up being ground related back at the light housings. I also think that trailer wiring has become very cheap and the insulation cracks real bad. Unless it's in real good condition a trailer wiring kit might be the solution.

 

[AJMBLAZER]

**** it.

 

[ktmoutfront]

Smart man. I have been dealing with wiring on trailers for the last 2 days. Lack of sleep has made me a little foggy. Threw my hands up and started over on all 3.

 

[AJMBLAZER]

I peeled back all the wire wrap and took apart the seven way plug without anything obvious showing up. Must be a break in the wire somewhere.

 

[ktmoutfront]

Fighting wiring issues on a brand new Wells Cargo trailer. They used to be good.

Wire nuts on the tail light wires.

 

[AJMBLAZER]

Nice.

 

[Wes Harden]

And scotch locks even worse in my book.

 

[ktmoutfront]

They are on everything built now.

 

[AJMBLAZER]

That’s what this one was wired with. I replaced them with sealed butt connectors. Nada.

 

[sweetk30]

had a enclosed years ago i fixed . the running lights up top on the back would go in/out bouncing down the road . found a un secured wire power for them getting rubbed when the torsion spring for the door went up/down . this caused the insulation to get buffed off and then as it went down the road and bouncing it would short / short / short / short . . .

 

[AJMBLAZER]

Well, I have rewired the entire trailer with a new plug also and everything works except for the right blinker and brakes. I am getting right side running lights now.

It’s something with the light housing itself. I played with it for most of an hour without success and I am just going to go replace it.

Oh, like this ground splice?

 

[AJMBLAZER]

Light’s work! Off getting the kids from school but should clean up the rest tonight.

 

[AJMBLAZER]

Guess I should add I sold the trailer last week. No reason to keep it and it was just sitting. Guy who bought it was tickled with it, drove 4 hours each way, and negotiated fairly.

Lights worked perfectly.

Thanks for the help guys.