Trailer Wiring Problems

[RM58]

I am rewiring a Jon boat trailer. I installed the new wiring today (wiring and plugs came with the new tail lights). Once I had completed the wiring and installed the new tail lights I hooked the trailer up to my truck to test the lights. The tail lights work fine. However the the signal lights and the brake lights are a different story. No matter which turn signal you turn on, both the right and left turn signals are both flashing. When I test them with a test light ( a device that you ground to your trailer and stick it into the wire to see if it has juice) the signal that you have on shows a bright light, but when it hook it to the other side of the trailer which is also blinking the light on the tester is very dim. I figured that it had something to do with the ground which is just a single white wire which connects to the trailer. I sanded the paint off where it attaches to the trailer to make sure that it was getting a good ground. This still didn't help. I then took the self taping screw out and replaced it with a bolt and nut thinking it might give me a better ground. Still the same problem. Also, neither brake light is working. I checked the plug on the truck with the tester and it is working perfectly. I know that I have the lights wired up properly. I did have to extend the length of the wires so I was wondering if this could have anything to do with the problems. Any suggestions would be appreciated.

Thanks

 

[kenmyfam]

Re: Trailer Wiring Problems

One bad connection or one bad ground somewhere will give you no end of problems.
If the vehicle tests out good with your tester then my guess with the information you give is a faulty ground.
What are you grounding to ?? and where does that piece connect. Once tightened up all the bolts holding my trailer together and cured a grounding problem that way.

 

[Bondo]

Re: Trailer Wiring Problems

Ayuh,...

It sounds like you Grounded to the Trailer,....

What about the Ground from the Trailer to the Tow unit..??

 

[Gary H NC]

Re: Trailer Wiring Problems

Look at this and double check your wiring,
http://www.etrailer.com/faq_wiring.aspx

 

[RM58]

Re: Trailer Wiring Problems

I attached the white ground wire to the side of the trailer coupling. The white ground wire that came with the plug was only about 14 inches long so that is the only place that I had to connect the ground. I did sand off the paint on that area very well so it could get a good ground. As for grounding to the tow vehicle, I assume that ground is completed inside the plug harness. All of my other trailers work fine when hooked to my truck.
Any other help would be appreciated as this is getting frustrating. It is the standard wiring bundle that comes with a set of tail lights. I ran the yellow and yellow/brown wires down the drivers side of the trailer and green and green/grown wires down the passenger side of the trailer and I made sure that I connected the correct wires to the tail lights.

Thanks

 

[Pony]

Re: Trailer Wiring Problems

I have installed a few of those light sets......there are really 3 places on them where they are gounded. The white wire from the connector (which you seem to have taken care of) and both light bezels. I would grind off the paint where the light bezels attach to the trailer and make sure the mounting bolts are in solid contact with the trailer frame (they will either ground through those bolts or have a seperate white ground wire...I have seen both)..........then coat with dielectric grease or vaseline. If all 3 of those places are ground really well, then you will need to investigate further.

 

[kenmyfam]

Re: Trailer Wiring Problems

Well........any luck yet ????

 

[Silvertip]

Re: Trailer Wiring Problems

There was no mention of what type of tow vehicle this trailer was towed by. If the tow vehicle has separate brake and turn signal bulbs (a vehicle with an amber turn signal in the rear for example) will not work properly with a standard four wire system unless a converter is added to the tow vehicle. Lots of vehicles today are made this way even though they do not use amber signals. You really have to look hard at the tail lights to see whether a single, dual filament bulb (which does work) or separate bulbs are used.

 

[reelfishin]

Re: Trailer Wiring Problems

Also, if the trailer is a tilt model, the right place to ground the lights is beyond the tilt hinge and on the main frame which the lights are bolted too. I've had many tilt style trailers that had intermittent or no lights when grounded through the tongue alone. You can also just add a ground strap between the tongue and main frame. The same goes for bolted together trailers, Load Rite for example, if the bolts that attach the side frame rails to the tongue are loose or rusty, light function will be erratic.

 

[RM58]

Re: Trailer Wiring Problems

Well I figured it out this afternoon a couple of hours after I made the post. It is a tilt trailer and the ground wasn't carrying over from the front half of the trailer to the back half of the trailer. I just ran a second ground wire from the tongue to the rear of the trailer and everything is now working perfectly. Reelfishin, you nailed it but I didn't see your post until now as I had been away from the computer since early this afternoon. Thanks for everyones help.

Randy