Trailer & Truck Light Question

[wvyen]

Hello,

I just got a new boat/trailer... When towing it home I had an electrical issue. When I would turn my headlights on my cruise control would shut off. When I pressed the brakes my dash lights would shut off, when I put my blinker on my dash lights would flash. The right brake light was very dim the whole time... It was very odd

The 4 pin plug looked a little worn like it had been drug down the road, so I decided to replace it today with a new 4 pin pug.
I connected wire by wire, to make sure I was connecting the right wire, with wire crimps the taped it up securely. When I was all finished and expected to see great results I now have no lights... What is going on here? Is it the trailer lights? Could it be my truck? What should I do?

Thanks in advance!

 

[colbyt]

Re: Trailer & Truck Light Question

This is a common sense thing. Unplug the trailer and if the truck works fine then there is a short or shorts in the trailer wiring. The good new is that a new trailer cable isn't all that much.

 

[wvyen]

Re: Trailer & Truck Light Question

This is a common sense thing. Unplug the trailer and if the truck works fine then there is a short or shorts in the trailer wiring. The good new is that a new trailer cable isn't all that much.

I wouldn't exaclty say it is as easy as common sense... My concern with the truck was that the receptor or wiring could be damaged and causing issues. If that was the case then I would end up rewiring the trailer and not resolving the issue. I am hoping to narrow down the problem first, then attack the problem.

 

[colbyt]

Re: Trailer & Truck Light Question

I surely meant no insult. Unplugging the trailer narrows it way down.

 

[wvyen]

Re: Trailer & Truck Light Question

No insult taken... I do appreciate the advice. To me there just seems like there are multiple variables and I just know where to start.

So I guess the next step is to just go ahead bite the bullet and replace the wiring on the trailer? Anything I can try before I do this?

 

[90stingray]

Re: Trailer & Truck Light Question

Start with a good ground on the trailer side. A bad ground does weird things. After that you can ring out each wire to see if its shorted or open before you rip everything out and change it.

 

[colbyt]

Re: Trailer & Truck Light Question

After the ground mentioned above you can trace the wires and look for visible damage. Critters and corrosion love to live in the light housings. You might start there. If you have a Harbor Freight close you might spend $4 for a trailer test light that plugs into your jack on the truck. I'm sure they sell them for mo $ at Lowes, Uhaul and HomeDepot.

 

[Mi duckdown]

Re: Trailer & Truck Light Question

You don't mention what type of truck. Some need a converter.
Check your four pin at the truck first with a test light.

 

[T_Herrod]

Re: Trailer & Truck Light Question

So I guess the next step is to just go ahead bite the bullet and replace the wiring on the trailer? Anything I can try before I do this?

Before gutting the wiring on the trailer check the following.
1 Insure that you have a good ground on both the trailer and tow vehicle. And be sure they are connected. Do not ground the trailer with the ball on the truck.
2 Use a good battery or battery charger and connect the ground to the white wire(ground) on the trailer connector.
3 Connect the positive lead to each circuit on the trailer. Brown is tail/marker lights Yellow and Green are turn/brake lights.
If they all function properly then connect the trailer to the tow vehicle and you should have lights.
Don't waste your time and money rewiring the trailer until you are absolutely sure that it needs to be done.
Good luck

 

[UncleWillie]

Re: Trailer & Truck Light Question

I wouldn't exactly say it is as easy as common sense... My concern with the truck was that the receptor or wiring could be damaged and causing issues. If that was the case then I would end up rewiring the trailer and not resolving the issue. I am hoping to narrow down the problem first, then attack the problem.

Be sure to follow your own advice!
Don't start replacing things until you know what really needs replacing.

The trailer can cause problems to appear in the truck, but not if it isn't connected!
Unplug the trailer.

If the problem is actually in the truck , unplugging the trailer will NOT fix the truck problem.
If the problem remains, it is in the truck.
If the problem vanishes, it is a trailer problem.