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moombabmf
04-05-2008, 02:20 AM
Ok,
So i get a new tundra last week and have been dieing to get my boat out and tow it home and get it cleaned out and and ready for this season. I back up to the trailer and plug in the lights and nothing! Do the whole wiggle the wires, nothing. I take the boat off my hitch and go to unplug the lights and they were on! So i set the toung down on the ball and the lights go off. Any of you guys have any idea where the short is. This is killing me!

seanpatsdad
04-05-2008, 03:27 AM
If no fuse is blowing it is probably not a short.I would check your ground wire.just a thought.
John

Membrain
04-05-2008, 11:55 AM
Maybe your boat wants a Dodge!?

Kidding!!! Sounds like a grounding issue!

zabooda
04-05-2008, 01:51 PM
Your ground wire to the trailer is disconnected and your back feeding at the tail lights at the common ground connection. Your hitch provides a high impedance ground which keeps your lights from lighting and when the trailer is seperated from the vehicle you lost what little ground you had and the circuit is feeding back through the other circuit.

Sled491
04-06-2008, 12:01 AM
I'm with Membrain :lol:

moombabmf
04-06-2008, 02:46 AM
thanks for the replies! Sprayed a bit of WD-40 and what do yoou know the lights work like a charm!

Buttafewcoe
04-06-2008, 04:37 AM
Yep, I was gonna recommend WD-40....either that or duct tape it!
.
B

moombabmf
04-06-2008, 09:28 PM
if duck tape and wd-40 doesent fix it nothing will!

bamaspiveys
04-06-2008, 11:12 PM
Huh?

How did WD-40 fix this?

zegm
04-06-2008, 11:39 PM
It acted like a cleaner and took the dirt off the contact point!
OK that's my statement and I am sticking with it.
I have had to replace the trailer plug on the Silverado due to corrosion from launching my fishing boat in salt water. It used to be that I could spray PB Blaster (a much better product than WD-40 if I might add) and it would clean the contacts enough so that they would work for a time. Finally I had to replace it. Now I shoot the new connector all the time to keep corrosion away!!! But I had the same problem, weird lights, turn on left turn signal and all would flash and other backfeeding issues.

JesseC
04-07-2008, 12:31 AM
Huh?

How did WD-40 fix this?

I am glad that I am not the only one that was thinking that, but then again who am I to question the power of WD-40 or duct tape. Universal tools like these should never be questioned!!!

tazz3069
04-07-2008, 09:19 AM
If you cant fix it, then Duct it.

moombabmf
04-08-2008, 02:34 AM
I am not sure how it fixed it but i can tell you they are fixed.

spyder
06-15-2011, 08:32 PM
i wanted to bump this thread, i am having the same issue.. but the WD-40 and duct tape aren't helping..

i tried the WD-40 on the hitch itself to the truck and the ball and trailer.. neither worked..

i put duct tape on the ball, but the trailer just dug through it

zabooda
06-15-2011, 11:35 PM
You probably have back feeding through your other light circuit. With the trailer disconnected, turn your tail lights on and they will light, leave them on and apply the brake and the lights should go off. If it does that then you have either no ground or a high resistance from your light sockets to ground. The path goes from the positive wire through the bulb to the negative side where the other bulb element is connected to and back out the non-lite positive side and other through other bulbs connected to ground. When you apply power to both elements then there is 12v at both ends so you get nothing. I'm still perplexed that the lights did something different when it is on the ball as the resistance would be the same (backfed and no ground through the ball) or less with a ground.

spyder
06-16-2011, 12:26 AM
You probably have back feeding through your other light circuit. With the trailer disconnected, turn your tail lights on and they will light, leave them on and apply the brake and the lights should go off. If it does that then you have either no ground or a high resistance from your light sockets to ground. The path goes from the positive wire through the bulb to the negative side where the other bulb element is connected to and back out the non-lite positive side and other through other bulbs connected to ground. When you apply power to both elements then there is 12v at both ends so you get nothing. I'm still perplexed that the lights did something different when it is on the ball as the resistance would be the same (backfed and no ground through the ball) or less with a ground.


i am going to start tomorrow by buying a new 7 - 5 pin adapter, see if thats the issue.

mmandley
06-16-2011, 09:27 AM
Im interested to hear the out come of this as well.

My first thoughts are the trailer ground is weak and this is threw the harness to the truck. Ultimatly the trailer grounds threw the harness and on the truck frame.

zabooda
06-16-2011, 12:48 PM
I would recommend checking the ground at the boat connector and you may need to jumper the ground at one of the lights to the frame if you want to use the frame as the return path for continuity. I'm not sure how the trailers lights are mounted but the lights may not always be grounded to the frame.

spyder
06-16-2011, 04:41 PM
I would recommend checking the ground at the boat connector and you may need to jumper the ground at one of the lights to the frame if you want to use the frame as the return path for continuity. I'm not sure how the trailers lights are mounted but the lights may not always be grounded to the frame.



i pulled the 4 rear lights out and checked the white wire, all still had a connection to the ground screw on the trailer.. so I am pretty sure the're grounding. I am still hoping it's the 7-5 pin adapter thats the issue.. going to try it out when I get home from work.

spyder
06-16-2011, 07:07 PM
well, i replaced the adapter and same thing... looking under my truck.. crazy rust.. do you think this ground could be the issue?

is there a way to test with a voltmeter or something? i really dont know anything about electric things

spyder
06-16-2011, 11:17 PM
and after messsing around all evening, we figured it out..

turns out the screw that connects the ground to the trailer was in bad shape, tried to unscrew it and it broke right off.... had to drill a new hole and use a new end, and all seems good.

happy to have figured out this issue.. keep this in mind down the road if you have this issue.