Trailer wiring question......

DirtMcGirt

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Joined
Nov 26, 2012
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21
Need to replace the plug on my trailer as it's beat up and corroded. It's a 92 Tracker Trailstar with what appeared to be a standard 4 plug connection. I cut the plug off, and there are 6 wires from the trailer.
Yellow
Brown
White
Then there are 3 sheathed together
Green
Green/Black
White

What are the additional wires for and where can I find a plug for this? I tried just hooking up the green assuming it's the right turn signal but it doesn't work. Tried every combination of the 3 and no luck. Thanks in advance.
 

colbyt

Master Chief Petty Officer
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Aug 9, 2012
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824
Re: Trailer wiring question......

I am not going to say it does not exist. But I have never seen just a plug. Normally you buy a new trailer wire kit for under $10. If you want to save yourself a lot grounding issues in the future just buy the on sale harborfreight magnetic lite kit and throw away the lights. It will have a cable with a ground wire to each light.

Your extra wires might be to side marker lights which should connect to the tail light wires.
 

DirtMcGirt

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Re: Trailer wiring question......

Thanks, I think at this point rewiring is the best option.
 

caverdan

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Nov 1, 2012
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Re: Trailer wiring question......

Just a wild guess.......but the two white wires should be ground to each light. The brown and green/black should be running or tail lights......depending on what you call them. The yellow and green wires should be left and right turn. I would bet you need the white wires hooked to ground before you will get the other wires to work.

I would start with a volt/ohm meter and make sure the plug from the vehicle was working properly. Then I would open up the tail lights and check the bulbs for continuety and the sockets for corrosion. With the lenses off you should be able to see where the wires run inside them. If everything looks good, I'd try wiring it with the whites to ground and try hooking up the running lights first.

If you do go for all new lights and wires....I'd spend the extra and get LED's.
Hope this helps some. :)
 

UncleWillie

Captain
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Oct 18, 2011
Messages
3,995
Re: Trailer wiring question......

...what appeared to be a standard 4 plug connection. I cut the plug off, and there are 6 wires from the trailer...

An Ohm Meter testing the cut off Plug Pins to the cut off Wire Stubs should tell you what went where.
 

2 Eagles

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Apr 4, 2011
Messages
206
Re: Trailer wiring question......

I would say that you had one Brown running down both sides & 2 Ground Wire or White Wires. What you thank is Green/Black is Green/Brown. The years have made the Brown look Black.

So what you need to do is attach:

1 Yellow to Yellow
2 Brown to Brown & Green/Brown
3 Green to Green
4 White to Whites
 

beardeddone

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Oct 26, 2012
Messages
164
Re: Trailer wiring question......

When I bought my boat a few months ago the right tail/brake light wasn't working so I checked the bulbs they were ok then got into checking the wires and how the trailer was wired and was going to replace the socket inners of the right light and turn signal to find out that both lights left and right were grounded right there in the rear of the trailer, the right ground bolt wasn't tight and about 3 turns out from being tight, I tightened the bold down on both lights and then it worked as it should, I also put light grease in the sockets...
 

UncleWillie

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Oct 18, 2011
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3,995
Re: Trailer wiring question......

I would say that you had one Brown running down both sides & 2 Ground Wire or White Wires. What you thank is Green/Black is Green/Brown. The years have made the Brown look Black.

So what you need to do is attach:

1 Yellow to Yellow
2 Brown to Brown & Green/Brown
3 Green to Green
4 White to Whites

The Order should Be;
1. White - Ground (Opposite Gender Pin)
2. Brown - Tail/Running Lights
3. Yellow - Left Brake/Turn Signals
4. Green - Right Brake/Turn Signals
5. Blue - Brake Actuator Signal or Reverse Brake Disable Signal

Is there any chance you were looking at a Flat 5 pin connector with 6 wires?


They sometimes have an extra ground to go with the brake wire.
Does your trailer have Electric Brakes?
Does your trailer have Surge Brakes with an Electric Solenoid to Disable brakes in Reverse?
 

DirtMcGirt

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Nov 26, 2012
Messages
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Re: Trailer wiring question......

You're right, this seemed to be the case. With all these connected the tail lights work, but the running are not. I used a tester to confirm I'm getting everything I need from the truck, and even tested wiring back to lights on side of trailer. Everything checks out fine, but the lights still don't work. I have replaced the bulbs. What else could the problem be? I see ground wires for both tails, but there is no ground wire for the running lights. Here is a picture of the back of running lights assembly.......any ideas? Possibly it's just corroded not allowing the light to work?


JfcvT.jpg
 

snowman48047

Petty Officer 1st Class
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Jul 24, 2008
Messages
371
Re: Trailer wiring question......

That metal tab on the back of the light needs to be cleaned, as well as where it attaches to the trailer. That is your ground.

Or, run a new white wire from that position (still clean everything) and run it to the front of the trailer and connect to the other white. This way you should get a better ground.
 

DirtMcGirt

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Nov 26, 2012
Messages
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Re: Trailer wiring question......

Makes sense. I did clean the metal off on both sides but that didn't seem to make it work either. Another thing I forgot to mention that made no sense to me.....when testing the wires at the lights on the trailer, I could not get a good ground when just clipping to multiple spots on the trailer. I ran a piece of wire from my bumper as the ground and then it checked out fine. Any clue as to why this might be the case?
 

UncleWillie

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Oct 18, 2011
Messages
3,995
Re: Trailer wiring question......

Sounds like a classic Ground Problem.

The Trailer Frame/Ground and the Truck Ground/Frame are not connected together.
Trace every inch of the White Wire from where it is attached to the Truck, through the connector, to where it is attached to the Trailer.
 

Bronlonius

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Oct 21, 2012
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145
Re: Trailer wiring question......

My experience with boat trailers is that grounding to the frame of the trailer rarely works. This is because:

1. The frame of the trailer is generally a bunch of pre-painted parts that are bolted or clamped together, so there's not a good conductive connection between each part.
2. It get's dipped in the water and rusty, so even if you bond all of the pieces of the frame together with little ground wires using ring terminals and star washers these connections generally end up corroding.
3. While sometimes the hitch and ball will make a ground connection between the trailer frame and tow vehicle, this usually isn't the case, since your receiver hitch is probably powder coated and not making a good connection with the frame of your tow vehicle.

On a trailer where the whole frame is welded together, it's a little more likely that you can get away with this, but on a boat, you're better off just running ground wires from the lights all the way up to the plug. Most trailer wiring kits have enough wire for turn/brake and tail, but they don't include enough wire for ground. The cost is so insignificant it's better to just use add ground wires all the way up to the plug instead of trying to troubleshoot the trailer frame's lack of conductivity.
 

Lone Duck

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Oct 17, 2007
Messages
868
Re: Trailer wiring question......

Run all ground wires directly from lights to plug. Same as power. That makes an independent elec. unit. It would work on a wood trailer. Solder and shrink tube all connections. when I rewire a trailer ,I run all my wire in a hose clamped to the frame. while you are at it, get L E D lights. Do it right do it once & go fishing.
 

DirtMcGirt

Cadet
Joined
Nov 26, 2012
Messages
21
Re: Trailer wiring question......

Run all ground wires directly from lights to plug. Same as power. That makes an independent elec. unit. It would work on a wood trailer. Solder and shrink tube all connections. when I rewire a trailer ,I run all my wire in a hose clamped to the frame. while you are at it, get L E D lights. Do it right do it once & go fishing.


Great, thanks for the replies everyone. Guess I'll just run ground wires from the running lights, should fix my problem. Thanks again.
 
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