Trailer lights not working

[cadfishjunkee]

I just found out my trailer lights are not working somehow, but brake lights are? I double checked the main connection to the truck and looks fine. Anyone have any troubleshooting techniques I can do or recommend? My tow vehicle is a 03 Dodge Ram 1500.

 

[tashasdaddy]

Re: Trailer lights not working

the way i read this is the lights work on the truck, and not on the trailer. the # 1 cause of trailer light failure is the ground between the trailer and tow vehicle. i personaly, have given up and ran a continous ground wire to every light and into the white ground wire on the plug. have not had a problem since, other than a bulb burning out. unplug you light during launch and retrieve.

 

[rickdb1boat]

Re: Trailer lights not working

And this may help you:

Brown wire is to the tail or parking lights
Green wire is to right turn signal/stoplight
Yellow wire is to the left turn signal/stoplight
White wire is to common or chassis ground....

 

[bruceb58]

Re: Trailer lights not working

Buy a meter and just start checking voltages at various points. Start at the vehicles connector and work your way back. Also, check the connector to make sure it is not corroded and take apart the connector to make sure all the wires are properly connected.

Although i agree grounds are often a problem, you don't need to run a seperate ground to every light. The trailer is a fine ground. Car manufacturers don't run seperate grounds to every light. The connections to the trailer ground can be a problem but you would have the exact same problem if you ran a seperate wire.

 

[Silvertip]

Re: Trailer lights not working

Actually, car manufacturers now need to run separate grounds to many lighting circuits because there is so much plastic involved. An inexpensive test light or a $10.00 meter available at Radio Shack can help troubleshooting. Looking at connectors is not a test. Measuring whats present or not present at the terminals is necessary.

 

[bruceb58]

Re: Trailer lights not working

Absolutely not true!

Actually, car manufacturers now need to run separate grounds to many lighting circuits because there is so much plastic involved.

 

[Silvertip]

Re: Trailer lights not working

Okey dokey!

 

[nathan104]

Re: Trailer lights not working

I had the exact same problem. My blinkers, flashers and brake lights worked but my taillights and side marker lights didn't. Bet your problem is the same as mine was. In order to properly ground and was stated above, good contact needs to be made in between the tow vehicle and trailer. This is through your hitch. I sanded the inside of my hitch(where the ball goes in) and made sure my ball was clean. After sanding the inside top and sides in my hitch, the problem was solved. Hope that helps you.

 

[bruceb58]

Re: Trailer lights not working

Nathan,

You cannot rely on the hitch ball for the ground. It has to be done through the electrical connector. The vehicle connector already has a ground in it. You just attatch the trailer side ground wire with a screw into the trailer .

 

[nathan104]

Re: Trailer lights not working

I did that but it didnt solve anything. I sanded an area around a small screw hole to remove the paint in order to give good contact between the ground wire and the trailer. Scrwed it in tight. Still had no tail lights. I bought one of the connector testers at walmart to check my connector on the truck and it showed that it was fine. Then I read on another forum about the connection between the ball and hitch. Tried that and it soved the problem.

 

[tashasdaddy]

Re: Trailer lights not working

thats why i ran an independent common, ground to eery fixture, and tied it into the harness.

 

[tymtogo69]

Re: Trailer lights not working

You can't rely on your hitch to ground your trailer, there is to much play in the ball mount and coupler assy. It might work fine while you are sitting in your driveway, but i bet they are loosing ground going down the road. You need to make sure your trailer is properly grounded trough the wiring harness.

 

[Dunaruna]

Re: Trailer lights not working

[colour=blue]What tashasdaddy did is by far the best way to solve a very common problem.

The reason car manufacturers run independent ground wires is because they do not rely on self tapping/captive screws/nuts/bolts, such as the ones that hold the CPU in place.

 

[DJ]

Re: Trailer lights not working

Your truck may have an independent fuse for trailer tow.

If it's blown, no power to trailer connector. Get out the owners manual and look at the fuse block diagram. Better yet, look up "trailer tow".