Running Lights don't work

Check for pulled off wire at the running lights. That's what was wrong with mine. Wires pulled clean off. Didn't have running lights but the the rear lights all worked.

Found it when I had to go under the RV to retrieve a ball for a kid. :B

EdBigley wrote:
Had that happen this summer on the first trip with new truck. Brake lights and turn signals worked, brakes worked, but no running lights. Turned out to be a blown fuse in the truck in the running light circuit.

Same thing in my Class C.....blown fuse in fuse box under hood.

Had that happen this summer on the first trip with new truck. Brake lights and turn signals worked, brakes worked, but no running lights. Turned out to be a blown fuse in the truck in the running light circuit.

Maybe the OP needs this presented a little clearer and simpler.

The brake LIGHTS and turn signals work off one connection in the pigtail hookup

The TAIL lights and clearance lights work off ANOTHER different connection

The BRAKES themselves are yet another different connection.

Three pin connections, and three electrical circuits are needed for the three functions above.

Now if your TAIL lights in the trailer work but not the clearance or marker lights, that's a horse of a different color.

You could help find the answer by re-examining the trailer lights to see if the tail lights are working as well as the brake and turn signal lights.

Start at the tow vehicle 7 pin connector. Do you have power to the pin? If no, the problem is in the tow vehicle.

If yes, plug in the TT cord and pierce the wire to the marker lights. Do you have power? If no, the problem is in the TT plug connection.

If yes, keep following the wire toward the lights testing. When you lose power, the problem is between the last reading with power and the first reading without power.

Use a volt meter. Set it to read DC volts. Turn the car's headlights on and make sure that the tail lights are illuminated. Place the black lead of your volt meter on pin one of your seven way connector. Place the red lead of your volt meter on pin three of the seven way connector. If you are reading approximately 12-13 volts, then the problem is somewhere in your trailer wiring. If you do not have a voltage reading, then the problem is with your car's wiring.

I had a similar problem recently. Turned out that the new receptacle in the truck bed (for a 5er) was not mounted securely to the bed wall, so the umbilical cord would not make a good connection. Once I tightened everything up the lights worked fine. You can do a search in some of the other categories and come up with other suggestions for troubleshooting.

Check if you have power coming from your vehicle running light circuit at the rear plug-in. If so then proceed to check your connector on the trailer. Sometimes those wires can vibrate loose inside the plug. If you dont have power at the vehicle then a fuse may have burnt out.