Tail Light Issue

[greenchicken]

Hi all,

Just posted picture of the completed TD.

One vital issue is the tail lights. Followed the instructions.... not much to get wrong. Everything lights up.... but I do not get break lights or directionals.

The tailer light have three wires: Lights (yellow), Break/Direcitonals (Brown), Ground (white).

All the colors match up, but I even if I reverse the Yellow and Brown I still get light only.

I use the same connection for my boat trailer and the directional work so I don't think it is the connections.

Any thoughts?

[troubleScottie]

First the color of the wires on the light and your harness do not have to match up.

The right side needs the running lights, right turn/stop and common.

The left side needs the running lights, left turn/stop and common.

A total of 4 unique wires.

Typical for a 4 wire system (in this order typically)
Common is white
Brown is running lights
left turn is yellow
right turn is green.

your lights' yellow should be connected to the brown
your lights' white to white
your lights' brown to the yellow or green.

From: https://www.etrailer.com/faq-wiring.aspx

Obviously, your colors may vary.

[Modstock]

Most electrical issues are with the ground.
Use serrated washers for a good ground. They bite into the metal.


Sent from my H1611 using Tapatalk

[GTS225]

Say, Green. Are these incandescent, or LED lamp assemblies?
If LED, I'm wondering if there was an internal assembly issue, and the brake/turn has it's polarity reversed.

Roger

[aggie79]

I believe you used an Ironton aluminum trailer. If so, there are four lighting circuits, brown, white, green, and yellow. As previous posters have said, the first place to start looking is by tracing your "hot" side circuits. Next, also as previously posted, I'd check to see that all lights have sufficient ground. On an old Harbor Freight trailer, I had issues with grounding, so I ran individual ground wires to each light and tied them directly together in the four-pin connector pig tail.

If lighting doesn't work after the first two suggestions, I'd next take a look at the tow vehicle side of things. I know you said your boat lights work fine, but do you have a factory trailer connector? If not, how did you tie into the tow vehicle lighting? If you tied the wiring directly, rather than using a powered convertor, the vehicle lighting may not be getting a strong enough current if trailer lighting is incandescent. If using convertor, it may have been damaged if trailer lighting was wired incorrectly.

[swoody126]

here is a pic of "standard" plug configuration

trailer-wiring-color-code-diagram-l-f3629d12b232a3b1.png (124.61 KiB) Viewed 1232 times

if i read your OP you have the 4-WIRE FLAT plug

note the location of each circuit in relationship to the ground

ground, tail, left, right (this is common)

here is a pic of common trailer wiring

wiring_diagram.jpg (23.3 KiB) Viewed 1232 times

you can buy a tool at HF, TSC or like source that looks like an ice pick with a light bulb inside and a wire coming out of the hande that has an aligator clip on it

https://www.tractorsupply.com/tsc/produ ... _vc=-10005

use of this tool can aid you in tracing your circuitry

beginning at the plugs work your way back toward the lights until you loose continuity

1st clip the tool to the bare post of the vehicle plug and test each female socket in the plug to assure your vehicle plug is working correctly

next clip the tool to the GROUND wire and using the point check each wire for continuity by pricking the wire thru the insulating layer (the light in the handle will confirm continuity)

there is a special plug that you can buy to confirm this if you aren't comfortable w/ pricking your wires

https://www.amazon.com/Curt-58260-4-Way ... ay&sr=8-18

as mentioned above and will forever be...

THE GROUND IS THE ABSODADGUMLUTELY MOST COMMON PROBLEM in trailer light wiring

sw

[GPW]

We installed a separate Ground wire on the FS , not depending on the trailer for a ground …

[GPW]

Yeah Cowboy , it’s so darn WET around here all the time those trailer ground connections quickly corrode and go away .. then the lights don’t work … ( plus we solder and shrink wrap all our connections too) ..

[1960es]

Sorry for the stupid question but GPW, what is FS?

[GPW]

OH, sorry , FoamStream …. what I named my trailer ...

[djohnsonnv]

Are you sure it is the trailer? When I first installed a wiring kit on my Kia all I could get was running lights no matter what trailer I was pulling.