Trailer Wiring

[capitol1]

When I plug in my boat trailer wiring all the lights work for about 2 minutes and than I blow a fuse in my truck. This is the 2nd truck I have used so the problem is in the boat trailer wiring. Could this be a ground issue?

Thanks

 

[Scott Danforth]

could be anything.

however it would be a short somewhere, probably in one of the lamp sockets or a wire is chaffed thru

time to pull a digital multi meter and a test light and start troubleshooting

 

[alldodge]

When I plug in my boat trailer wiring all the lights work for about 2 minutes and than I blow a fuse in my truck. This is the 2nd truck I have used so the problem is in the boat trailer wiring. Could this be a ground issue?

Thanks

Which Truck and what size fuse?
Don't know, but wonder if it has something to do with LED's in the truck and incandescent bulbs in the trailer

 

[dingbat]

Could this be a ground issue?

Take your voltmeter and measure the resistance (lowest scaling factor) between ground point on the trailer and the ground pin in the connector.

Touch probes to determine the "baseline" resistance (zero) of the probes.
A good ground should read 0 ohms. 0.5 ohms max.

I suspect you have a short in the wiring harness..........somewhere.

Two way to short this out......remove the ground connection on the trailer. Check continuity between each pin in the trailer side harness and the ground point on the trailer. Continuity = problem in that circuit.

If that doesn't turn up anything, connect a long piece of wire (to get to back of trailer) to your primary ground connection. Then check the voltage on each circuit (light) referenced to the ground wire.

A low voltage reading in a circuit (light) confirms a compromised power wire. Corrosion and or broken wires are typically the culprit here.

 

[poconojoe]

You have a short somewhere. A wire is frayed and touching ground or a light could have a short to ground. Does it happen immediately or only when you turn on the running lights or turn on one of the turn signals? You can narrow it down by those choices.

Rewiring a trailer is usually not a big deal. Sometimes it's not worth the trouble chasing down a problem, especially if your trailer has some years on it. Try for a bit, but if you find yourself spending hours, just buy a complete kit. They are not expensive in my view and while you're at it, opt for LED lights. You won't be constantly changing bulbs.

If you do rewire it:
Do not use the frame of the trailer to carry the ground. Run a ground wire from the tongue to the first light, then from there to the next light, then to the next, etc.

Use the old wire to pull in the new wire. Strip the ends of the wires, hook them around each other (old wire and new wire), stagger them if need be (you don't want a big lump), then tape it good with electrical tape. Have someone feed the new wire while you gently pull in the old wire out.

 

[Chris1956]

I would measure the resistance of the brake light filament of the tail light bulb. Now measure the resistance of the green wire and yellow wire individually, and see how close you come to that resistance reading. Lower resistance means a short exists.

Measure the resistance of the tail light filament in the bulb and half it. Now measure the resistance on the brown wire and see how close it is. Trailers often have marker bulbs, which will also be on this circuit. They will lower the resistance value as well. You could always remove all the bulbs and check for resistance to ground. In this case, resistance should be infinite, if no shorts exist.

There are wattage ratings for the bulbs on your trailer. If you add up the wattage, you can see if that exceeds the fuse capacity on your truck. LED bulbs take far less power than incandescent bulbs, so that could be an issue.

 

[poconojoe]

When I plug in my boat trailer wiring all the lights work for about 2 minutes and than I blow a fuse in my truck. This is the 2nd truck I have used so the problem is in the boat trailer wiring. Could this be a ground issue?

Thanks

If they work for about two minutes, are you turning anything on at that time, such as a turn signal, brake light or running light?
If you are, then that will point to the circuit that has the problem.

How old is the trailer wiring?

Is the trailer used in salt water?

Check all the light fixtures. Water can get inside them causing corrosion.

Check every spot where wires enter through the frame for chafing.

Defective trailer wiring can be very frustrating. One day it seems to work fine and just when you are hooked up and ready to go fishing, the lights don't work.

As I stated in my previous post, if you're spending too much time hunting this down, time for a rewire. It's not that difficult or expensive. Buy the whole kit with all the wire, LED fixtures and connectors. Measure the length of your trailer and buy the kit with the proper length wire.


The other option would be buying one of those temporary kits. They have the plug, wire and two magnetic tail lights. That's a quick temporary fix, but it's best to rewire the trailer and be done with it.

 

[dingbat]

If you do rewire it:
Do not use the frame of the trailer to carry the ground. Run a ground wire from the tongue to the first light, then from there to the next light, then to the next,

Daisy chaining ground wires is never a good idea.

The possible failure rates grows exponentially with each connection

I’m no fan of multiple ground wires for a number of reason, but should you choose to do so, run each ground wire from the light all the way back to a common ground point.
One failure...one light

 

[poconojoe]

Daisy chaining ground wires is never a good idea.

The possible failure rates grows exponentially with each connection

I’m no fan of multiple ground wires for a number of reason, but should you choose to do so, run each ground wire from the light all the way back to a common ground point.
One failure...one light

Ah, you are quite correct! If there were a problem with a splice at one light, other lights down the line might be affected.
I stand corrected! I guess I wasn't thinking when I wrote that.
Yes, it would be better to run the ground to a central location, then from that point to each light.