# Trailer wiring..



## Rough Rooster (Feb 7, 2015)

Do you have a good "ground" connection from vehicle to trailer?
Usually a white wire. If no ground then that will explain the crazy lights.

RR


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## mchipser (Sep 21, 2009)

I think I do, I drilled a new hole next to the wire box, I think you can see it in the picture..


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## r___r (May 5, 2015)

Hard to tell in the picture, but, it looks to me like the ground connection is making contact to the paint on the trailer. Disconnect that connection; wire brush the paint away on both sides where the bolt, washer, and ring terminal make contact to the metal of the trailer.

If you've already done that, then my pardon this post.

Good luck,

Rich


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## Colbyt (Jan 27, 2014)

mchipser said:


> I think I do, I drilled a new hole next to the wire box, I think you can see it in the picture..



No insult intended. If it is a cheaply wired trailer (like 95% of them) it relies on the individual grounds for the lights though the physical connection at each fixture or a ground wire at each fixture so each ground needs to be verified.

All you need to test is a patch cord and a 12 volt battery to test one light at a time. On vehicles with lighting converters you run the risk of killing the converter with faulty wiring.

If you have to rewire run a dedicated ground to each fixture and solve your future problems for a very long time.


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## mchipser (Sep 21, 2009)

I did notice one of the marker lights didn't have a ground, like the new one i put on.. Also I didn't see any ground terminals on the rear lights... 

Ill take a look and see what I can find tonight.. Thanks for the help..


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## 1985gt (Jan 8, 2011)

Redo the trailer, there is a short some place. A lot of trailers were wired with scotch locks, they are know to fail. 

When you re wire the trailer run all of you wires in steel conduit. The plastic stuff is easier to damage. 

You could go and trace all the wires and find out what ones are worn through the insulation and touching, but it's quicker just to redo it. It sounds like you have spend a bit on this trailer already no reason to cut corners now.

By all means check the tow vehicle also, but if the tester you have is indicating it's fine it most likely is.


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## BrowneBearLLC (Apr 8, 2015)

I did not read all of the other posts; however, 99% of the time it is a bad ground. Also, the ground going to the truck through the ball hitch can make a big difference, I just experienced this the other day myself. Hope this helps


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## mchipser (Sep 21, 2009)

1985gt said:


> Redo the trailer, there is a short some place. A lot of trailers were wired with scotch locks, they are know to fail.


That is exactly what this has on it..


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## mchipser (Sep 21, 2009)

Based on this, I might first try to clean all the points where a ground should be and ensure the marker light has a ground wire..

http://www.etrailer.com/question-36130.html


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## mchipser (Sep 21, 2009)

I think i know why the lights are not working as designed...

Based on my assumption the color codes inside the junction box i purchased was standard.... they are not..

http://www.conntek.com/products.asp?id=237

Right turn on trailer = green, junction box = brown
Left turn on trailer = yellow, junction box = red
marker / tail lights on trailer = brown, junction box = green.


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## iamrfixit (Jan 30, 2011)

mchipser said:


> I think i know why the lights are not working as designed...
> 
> Based on my assumption the color codes inside the junction box i purchased was standard.... they are not..
> 
> ...




That happens a lot these days depending on brand of wiring components. Some adhere to the standard colors and some don't. You will need a test light to correctly identify the wires.

You don't say what your tow vehicle is, if your tow rig has amber rear turn signals you will need a signal converter on the vehicle to work with the trailer.


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## mchipser (Sep 21, 2009)

iamrfixit said:


> That happens a lot these days depending on brand of wiring components. Some adhere to the standard colors and some don't. You will need a test light to correctly identify the wires.
> 
> You don't say what your tow vehicle is, if your tow rig has amber rear turn signals you will need a signal converter on the vehicle to work with the trailer.


sorry.. The tow vehicle is a 2005 Tacoma.. I matched the wires to the ones I posted above, and it seems to work like I would expect.. There is one problem though.. none of my marker lights are working.. I tested the new pin and there is no power going to it.. I put the tester i had back on and sure enough the TM light doesn't light up when i turn on the lights.. 

I guess there is something wrong with my truck now.. if it isn't one thing its another..

The picture below.. The head lights are on, and the hazards.. If i read everything correctly the hazards will show on the middle and right lights (LB / RB) and the head lights being on should illuminate the left light (TM) I think that means Trailer Marker, which isn't lighting up...


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## Rough Rooster (Feb 7, 2015)

So now replace blown fuse(s) on marker light circuit of truck.

RR


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