- My Forums
- Tiger Rant
- LSU Recruiting
- SEC Rant
- Saints Talk
- Pelicans Talk
- More Sports Board
- Fantasy Sports
- Golf Board
- Soccer Board
- O-T Lounge
- Tech Board
- Home/Garden Board
- Outdoor Board
- Health/Fitness Board
- Movie/TV Board
- Book Board
- Music Board
- Political Talk
- Money Talk
- Fark Board
- Gaming Board
- Travel Board
- Food/Drink Board
- Ticket Exchange
- TD Help Board
Customize My Forums- View All Forums
- Show Left Links
- Topic Sort Options
- Trending Topics
- Recent Topics
- Active Topics
Started By
Message
Looking for help with an issue with my boat trailer lights
Posted on 7/12/20 at 8:38 pm
Posted on 7/12/20 at 8:38 pm
When the truck headlights are on auto, and it’s daytime, the brake lights and turn signals on the back of the trailer both work (left and right). Again, Please note the headlights aren’t on as it’s light out.
Now when it’s at night, and the headlights are now on, the back left brake light goes dark. No turn signal, running light or brake light.
Obviously some wires are crossed. Anyone have some quick tips to solve this issue?
Now when it’s at night, and the headlights are now on, the back left brake light goes dark. No turn signal, running light or brake light.
Obviously some wires are crossed. Anyone have some quick tips to solve this issue?
5
Posted on 7/12/20 at 9:45 pm to hedgehog
My son had a similar issue and we fixed it by replacing the trailer 7 way connector on the truck bumper. It had corrosion inside. I used a tester I bought off of ebay and it proved its worth.
Posted on 7/12/20 at 9:51 pm to hedgehog
Sorry I have nothing useful to post. I just came here to say frick trailer lights. That is all.
Posted on 7/13/20 at 8:19 am to hedgehog
First thing I would do is check the pins at the truck connector, as suggested above. If it's a newer truck they often have the connector diagram on the spring loaded cover (which pin does what). Get a multimeter and check that the correct pins show 12 volts when they should (brake light pin shows 12v when brakes pressed, running light pin shows 12 when the lights are on). This is the easiest thing to check. If everything is ok there you know it's the trailer. If it isnt, theres a problem with your truck, most likely a messed up ground.
With the trailer the first thing you always do is verify that there is a good ground. Sometimes this is done through the 4 pin connector and sometimes through the hitch ball. Easy to determine, you'll either have 4 wires in the connector or 3. Verify the grounds are ok, and go backwards from there.
FWIW, my policy with trailers is always rip everything out and put new stuff. It's usually quicker than troubleshooting. They often use normal butt splices, shitty crimp on terminals, etc and all that stuff quickly falls apart with dunking in water and bouncing down the highway.
With the trailer the first thing you always do is verify that there is a good ground. Sometimes this is done through the 4 pin connector and sometimes through the hitch ball. Easy to determine, you'll either have 4 wires in the connector or 3. Verify the grounds are ok, and go backwards from there.
FWIW, my policy with trailers is always rip everything out and put new stuff. It's usually quicker than troubleshooting. They often use normal butt splices, shitty crimp on terminals, etc and all that stuff quickly falls apart with dunking in water and bouncing down the highway.
Posted on 7/13/20 at 8:36 am to DownshiftAndFloorIt
quote:
most likely a messed up ground.
This is the most common issue I've ran across.
As Downshift said, sometimes it's grounded thru the connector or sometimes it is grounded thru the ball.
If it is grounded thru the connector a lot of the times they connect the ground wire to the trailer frame. Then connect all the grounds from each light to the frame.
It's a cost cutting method. The issue with this is where they connect said grounds to trailer frame and corrosion over time. Either the connector itself or trailer (if galvanized).
A bad ground will cause all kinds of weird issues as you're seeing. I would start by checking there.
Once ground is confirmed I would start checking the 7pin plug on the truck with a multi-meter. Have someone in the truck operating the lights/signals while you are checking to make things easier.
This is why every time I rewire a trailer I pull the ground wire to each light and connect it directly.
It cuts out all the issues with using the frame as a ground.
Posted on 7/13/20 at 8:37 am to DownshiftAndFloorIt
quote:
Verify the grounds are ok, and go backwards from there
Posted on 7/13/20 at 8:42 am to southern686
quote:
This is why every time I rewire a trailer I pull the ground wire to each light and connect it directly.
It cuts out all the issues with using the frame as a ground.
As is the correct way to do it. I try to keep every connection up near the ball, to eliminate dunking connections and splices as much as practical. No connector is 100% submersible unless it is epoxy encased, and nobody got time for that wiring a trailer.
Posted on 7/13/20 at 8:48 am to DownshiftAndFloorIt
All solid advise, if you have surge brakes the ground issue is even worse with a trailer frame ground setup.
Harbor freight has decent and inexpensive marine butt slice connectors and marine shrink wrap.
Harbor freight has decent and inexpensive marine butt slice connectors and marine shrink wrap.
Posted on 7/13/20 at 9:36 am to hedgehog
First thing to do is check the ground on the trailer and redo it.
Not saying it’s always the ground. Just 99.99% of the time.
Not saying it’s always the ground. Just 99.99% of the time.
Posted on 7/13/20 at 10:07 am to DownshiftAndFloorIt
quote:
I try to keep every connection up near the ball, to eliminate dunking connections and splices as much as practical. No connector is 100% submersible
Yes, very true.
I always ordered the same things from amazon.
-A 7 pin connector that comes with a 10' pigtail and small junction box. The junction box has screw terminals for connecting all the lights with ring connectors.
-2 conductor cable (footage varies per trailer)
-Heat shrink butt splices
I mount the junction box on the tongue, coil the the spare between it and 7 pin plug.
I then run to each light with a 2 conductor cable. This allows each light to be independently wired from others. No splicing common wires multiple times for multiple lights. No jumpers.
I make the connection at the lights with a butt splice, and then heat shrink them to seal them. This method allows you to avoid the mess with taping them.
I bring all cables into the junction box, install ring terminals, and terminate accordingly. Obviously you'll have multiple wires on some terminals, like the ground and running lights.
It is far more work to do it this way but once I'm done I know its right and will last me many years without issue.
I just hate having to splice/jump wires like the ground multiple times in the rear of the trailer or having 3 wires to one butt splice.
It only adds another fail point.
Posted on 7/13/20 at 10:10 am to hedgehog
Ground. Its always the ground. All trailer light issues are a grounding issue....almost.
If it ain't a ground the only thing to do is use a multimeter at the truck and make sure the male end is functioning. If it is ring the trailer wires out although if they worked before and nothing has been done to them it is a ground. Always a ground.
The vehicle specific harnesses that most vehicles use today work great but in my experience when they fail they do so catastrophically without any indication they are going to do so. If it is done the old fashioned way by cutting the vehicle wires and twisting them together and taping you could have a bad joint. if it was done with the damned blue crimp on taps they also fail pretty regularly....but if it is a realatively new vehicle it probably has the plug in harness and in my experience they don't go bad they just fail compeletely with no symptoms...
If it ain't a ground the only thing to do is use a multimeter at the truck and make sure the male end is functioning. If it is ring the trailer wires out although if they worked before and nothing has been done to them it is a ground. Always a ground.
The vehicle specific harnesses that most vehicles use today work great but in my experience when they fail they do so catastrophically without any indication they are going to do so. If it is done the old fashioned way by cutting the vehicle wires and twisting them together and taping you could have a bad joint. if it was done with the damned blue crimp on taps they also fail pretty regularly....but if it is a realatively new vehicle it probably has the plug in harness and in my experience they don't go bad they just fail compeletely with no symptoms...
Posted on 7/13/20 at 10:24 am to Nodust
Does sound like a ground issue, the ground might be corroded enough to not be able to take the extra current with the running lights on.
Use the heat-shrink butt connectors if you redo any of the connections.
I have my white grounded to the frame and each light grounded to the frame using ring terminals and self-tapping screws with the screw ends ground flush. But I did go back and prime both sides and sprayed them with undercoating to keep them sealed and protected. Every wire connection is done with heat-shrink type connectors.
I upgraded to LED, and the ones I bought had a separate ground wire. My old ones used one of the mounting bolts to make the ground to the trailer frame, or wire if you ran a separate ground.
If it helps:
White is ground
Brown is Tail Lights / Marker Lights
Green is Right Turn Signal
Yellow is Left Turn Signal
Use the heat-shrink butt connectors if you redo any of the connections.
I have my white grounded to the frame and each light grounded to the frame using ring terminals and self-tapping screws with the screw ends ground flush. But I did go back and prime both sides and sprayed them with undercoating to keep them sealed and protected. Every wire connection is done with heat-shrink type connectors.
I upgraded to LED, and the ones I bought had a separate ground wire. My old ones used one of the mounting bolts to make the ground to the trailer frame, or wire if you ran a separate ground.
If it helps:
White is ground
Brown is Tail Lights / Marker Lights
Green is Right Turn Signal
Yellow is Left Turn Signal
Posted on 7/13/20 at 5:21 pm to td1
The ground is connected to the trailer frame beneath the spot where the V meets the neck. Should I clean the ground and see if it fixes the issue? Today I went and purchased a new 7 to 4 pin adapter with built-in test lights to verify wire continuity.
Posted on 7/13/20 at 6:19 pm to hedgehog
Yes, unbolt it and check for rust under washers. Brush off any bad stuff and put new ring terminal on wire, bolt back up.
This post was edited on 7/13/20 at 6:22 pm
Posted on 7/14/20 at 8:42 pm to 24nights
So I cleaned the ground wire at the neck and the ground wire at the left tail light. And now everything works! I am pretty sure the ground at the taillight wasn’t touching enough metal and that was the issue. Thx for the help.
Posted on 7/14/20 at 9:53 pm to hedgehog
Page 1 of 1
Popular
Back to top
Follow TigerDroppings for LSU Football News