Trailer Wiring Problems

[Trophycats]

Guys I have a problem and I have pulled my last hair out trying to figure it out, and take in mind I am not a genius when it comes to this sort of thing.

A couple of days ago as i got off the river about midnight, my triler lights kinda flickered while sitting in the parking lot, then went out. I jiggled the connection where the 4-way goes into the truck and they came back on. However on the way home, they went out and wouldnt come back on.

I checked the wires comeing out of the truck and i cant get a signal on the Brown Wire. I hooked my truck up to my buddies boat and I had turn lights..hazard lights and brake lights but NO running lights.

Came back home and hooked the truck up to my boat and i have nothing..zilch.

This is driving me nuts. I would think that i would have the same thing on my boat as I had on his boat, at least hazard and brake lights and turn lights.

Thanks in advance and any help would be appreciated..Warren

[PRO V LE]

The most common problem is a poor ground, do NOT rely on the hitch and ball to make a connection. The white wire needs to be attached to a clean and tight metal (no paint) area on the trailer. Same thing on the tow vehicle.
The running lights are on a seperate fuse, do all the lights work OK on the truck?

[Trophycats]

Everything works fine on the truck...no issues whatsoever.

[fisheater]

Short in a bulb assembly can burn out the little box that connects your electric to your plug in-truck side-.Sorry cant remember the name of it-power converter mayby???I had one melt down on me and thats what it was.

[Trophycats]

Are you talking about the part where the 4way plugs into? If so, how hard is that to replace? I also noticed that each light has its own ground, IF one of those grounds is bad would it prevent the whole deal from working?

[fisheater]

Its easy but that little box is high for my jeep so i bought the cheapest one and spliced it in so it would work with my jeep.Im poor like that lol.Just trace the wires on your truck side from the four way and youll find it.If it looks melted or has the odor of burnt plastic replace it.
Yep if one of those are bad youll have to replace it since its sealed.If its bad and its shorting it will cause haywire,The little box im talking about is where the short should stop so it wont burn up your tow vehicle electronics.Forgot the name but if you cant find out ill find out,let me know.

[R19]

Poor /weak ground will make trailer lights do some strange things. One minute they work next minute they partically work then some times nothing...just depends on how good of a connection you have.

I would start with the trailer first.

Troubleshooting...You need to determine if the trailer or truck is the problem. Do not use the truck as the power or ground supply. If it works off a 12v battery then the truck is the problem. If you use a 12v battery and everything works then start troublshooting the truck.

Get a 12V battery (I back my lawn mower up to the trailer) a set of jumper cables and some scrap jumper wires (3-4ft of stero speaker wire) Take ground from the battery and attach the other end of the jumper cable to the trailer frame...a good spot will be where bare metal is on the frame. On most trailers that is where the saftey chains hook up.

Then get the positive lead jumper cable and attach a small jumper wire to the clip...this will be the power supply. Touch the hot wire to the three male post on the trailer plug one post at a time, You will need somebody with you to walk around and look at the light to see if something is not working while you hold the wire on the post.

I have drew a blank and cant remember which color does what but...one of the male post will light up left turn,one will be right turn and the other post will light up every light all at the same time. If you have a light out go to that light and look for a bad ground.

That will check to see if the lights have a ground problem at the light assembly...You also need to check the ground in the plug and make sure it has ground...All trailers will have a white wire that comes from the four prong plug that attaches to the trailer...most of them connect at the saftey chains on the tounge. Disconnect the ground jumper cable from the trailer frame and attach a jumper speaker wire to it. Touch the jumper ground wire to the trailer plug at the white wire... it should be the female part of the plug.

Then repeat the procedure of touching the hot wire to the male post...be careful when you have the hot and ground speaker wires at the plug at the same time. That is a tight area to have hot and ground wires so close to each other. Do not touch the hot and ground together because it will scare you to death and possibly shot some bulbs or at least shoot your nerves. If you have light trouble look for a loose ground/bad connection on the trailer where the white wire ataches to the frame(probabbly at the saftey chains)


All lights on the boat are grounded to the frame. Most boat manufactures attach the ground wire with a pop rivet and over a period of time thre rivet will work loose. Check every light on the trailer for a loose connection. You shoud see a white wire that will come from the light assembly and goround to the trailer. If it is loose drill out the pop rivet and install a bolt with a self locking tap. Sometimes it impossible to get to the back side of a bolt to install a tap that is when I use a self tapping bolt.

Allright you have established groung from the battery to the trailer frame and everything works. You have established ground to the traile plug and everyting works...The problem is in the Truck. If it is the truck reply back and I will give you some suggestions on to make sure you truck is transfeering ground to the trailer. If you need to talk to me PM me your phone number and I will walk you through the procedure.


R19

[billm_usa1]

Assuming that this is an F-150. There separate fuses for the tralier lights. The Fuse box is under the hood. The Flickering and stuff does relate to a bad ground wire somewhere.

[MsgMills]

Assuming that this is an F-150. There separate fuses for the tralier lights. The Fuse box is under the hood. The Flickering and stuff does relate to a bad ground wire somewhere.

On my F-150 the fuse box is up under the passenger side floor area. My truck came with a tow package and has a separate fuse for each light action on a trailer. I too thought something was wrong with my trailer lights a few times, but I had just popped a couple of fuses.

[hooksetter]

The converter box that some are talking about is only used if your vehicle has a 3 bulb system for running/parking lights, brake light, and turn signal. Your trailor is set up as a 2 bulb system with the brake and turn sharing the same element in the bulb. I agree its probably a bad ground and its probably on the trailor side since your buddy's lights worked better than yours. You can use a battery charger as a power supply as well instead of the lawn mower that one mentioned by taking the black (negative) and hook it to the frame of the trailor and use the red (positive) to hit the 3 males on the trailor plug. Off the top of my head I can't remember which is which but one will run left turn/brake, right turn/brake and the third will be the running lights
Reply if you need further help

[Trophycats]

Thanks guys..i will have to wait till friday to check it out, but at least i have a place to start..will post how it goes..thanks again..warren

[GeoFisher]

Poor /weak ground will make trailer lights do some strange things. One minute they work next minute they partically work then some times nothing...just depends on how good of a connection you have.

I would start with the trailer first.

Troubleshooting...You need to determine if the trailer or truck is the problem. Do not use the truck as the power or ground supply. If it works off a 12v battery then the truck is the problem. If you use a 12v battery and everything works then start troublshooting the truck.

Get a 12V battery (I back my lawn mower up to the trailer) a set of jumper cables and some scrap jumper wires (3-4ft of stero speaker wire) Take ground from the battery and attach the other end of the jumper cable to the trailer frame...a good spot will be where bare metal is on the frame. On most trailers that is where the saftey chains hook up.

Then get the positive lead jumper cable and attach a small jumper wire to the clip...this will be the power supply. Touch the hot wire to the three male post on the trailer plug one post at a time, You will need somebody with you to walk around and look at the light to see if something is not working while you hold the wire on the post.

I have drew a blank and cant remember which color does what but...one of the male post will light up left turn,one will be right turn and the other post will light up every light all at the same time. If you have a light out go to that light and look for a bad ground.

That will check to see if the lights have a ground problem at the light assembly...You also need to check the ground in the plug and make sure it has ground...All trailers will have a white wire that comes from the four prong plug that attaches to the trailer...most of them connect at the saftey chains on the tounge. Disconnect the ground jumper cable from the trailer frame and attach a jumper speaker wire to it. Touch the jumper ground wire to the trailer plug at the white wire... it should be the female part of the plug.

Then repeat the procedure of touching the hot wire to the male post...be careful when you have the hot and ground speaker wires at the plug at the same time. That is a tight area to have hot and ground wires so close to each other. Do not touch the hot and ground together because it will scare you to death and possibly shot some bulbs or at least shoot your nerves. If you have light trouble look for a loose ground/bad connection on the trailer where the white wire ataches to the frame(probabbly at the saftey chains)


All lights on the boat are grounded to the frame. Most boat manufactures attach the ground wire with a pop rivet and over a period of time thre rivet will work loose. Check every light on the trailer for a loose connection. You shoud see a white wire that will come from the light assembly and goround to the trailer. If it is loose drill out the pop rivet and install a bolt with a self locking tap. Sometimes it impossible to get to the back side of a bolt to install a tap that is when I use a self tapping bolt.

Allright you have established groung from the battery to the trailer frame and everything works. You have established ground to the traile plug and everyting works...The problem is in the Truck. If it is the truck reply back and I will give you some suggestions on to make sure you truck is transfeering ground to the trailer. If you need to talk to me PM me your phone number and I will walk you through the procedure.


R19

Ground is probably the issue...............

If your trailer has a little rust, that can cause the ground not to work very well, especially if it is grounding via the trailer.

The BEST bet, to resolve ground, is to run a ground wire WITH your other wires to the back and instead of grounding the lights with a screw to the trailer, wire them to the new ground wire you ran.

I've had TONS of problems with lights and ground..........RUNNING a new wire fixed all the problems.........

ALSO you can eliminate a lot of headache, by getting a tester from wally world or U-Haul. You plug it into your 4-way,and if it lights up, you're GOOD, if not, our wiring on the tow vehicle is bad, or a fuse is blown.

One other thing.........if the trailer has running lights, you can have problems with ground, etc, etc, if you have cracked one of those lights, and exposed it, etc, etc......

I hope this helps.

Later,

Geo