Trailer lights help needed

[randyjaco]

The running lights on my trailer went out. All the trailer turn signals and the brake lights are working fine. None of the bulbs are blown. A while back, while connecting the trailer to my Tacoma truck, I got a spark while plugging it in. I couldn't find a blown fuse. So I don't know if the problem is with the truck or trailer. The truck lights seem to work fine, but they are not making the trailer lights function. Can someone please tell me which color wire make the circuit for the running lights?

 

[Janderso]

I’ll be waiting for a smart fellow to help out.
The purpose of my post, in my experience 99.9% of the time the issue is with the trailer wiring.
Scotch locks and other poor connection methods are used in an application that is exposed to the weather causing corrosion, high resistance and other issues.

 

[Bi11Hudson]

Most modern pickups have separate circuits for the trailer plug. Especially those that came from the factory with towing gear. My trailers all use a 6 wire connector, so I don't know which wire is for the running lights. As stated above, the problem probably lies with the trailer. But a blown fuse will be on the truck end. The WHITE wire is ground, of that I'm sure. Connecting a test light from that to the other three will quickly identify which is which. When testing, I usually set the 4 way flasher going, that helps isolate things quickly.

My most recent truck was a Chev DuraMax 3/4 ton. There was a relay panel, with fuses, immediately adjacent the truck fuse panel under the hood. A fuse for the trailer circuits is most likely under the hood rather than in the dash.

.

 

[lordbeezer]

Most are brown and yellow

 

[lordbeezer]

Test light should give the answer.

 

[John O]

Standard here is
white-ground
brown-tail lights
green-right turn/brake
yellow-left turn/brake
I have seen many wired different but the majority are this way.

 

[682bear]

On a 4 wire plug, the brown wire is normally for the driving lights... I would assume that is true for a 5 wire plug, but I'm not sure.

I would guess, if it sparked as you were plugging it in, that the wire has a short to the trailer frame somewhere... check everywhere the wire comes in contact with the metal to check for cracked or worn insulation.

In my experience, the cheap harnesses last 3-4 years before becoming problematic... at which point they just need to be replaced.

-Bear

 

[RandyWilson]

Year and model, please, so I can pull up a wiring diagram.

 

[jocat54]

I had the same thing happen on my 2014 Ram and it was a fuse under the hood by the main fuse panel-------had to order the replacement fuse no one carried it. Did southern engineer the fuse until the right one got here.

 

[RandyWilson]

I'm heading to bed, so I picked a random example, '19 Taco 3.5L. The trailer running lights have their own relay and 30A fuse in the relay box under the hood.