Hey guys, I have a 2001 Dakota Sport 4x4 with the 4.7. My rear running lights recently went out. Brake, reverse, and turn signal/flashers work. I started by checking the fuse (#4 on the dash fuse box) and it's fine. I've since replaced both bulbs, the park lamp relay and the switch on the dash and have nothing. I've inspected all the wiring and cant find anything obvious that's worn, corroded or cut. Is there a fuse or relay that plays in to the circuit I missed? Thanks!

 

Are the front marker lights working? They are on the park lamp relay as well. If yes, you can rule out the fuse, relay, switch, and CTM.
The CTM controls these via the park lamp relay.

Can you hear/feel the park lamp relay clicking when you turn the lights on?

The brake lights use the same ground as the park lamps.

 

The headlights work fine as well as the brake lights and all the other functions work and I can hear the park relay switch. I swapped the horn relay and park lamp relay as they are the same. Horn still worked but still no running lights. I just bought some test equipment and guess I'm chasing wires now

 

Just to clarify, are ALL of the running lights not working? Front and back or just the back?

If you hear the park lamp relay click then you can rule out the CTM, switch, and the fuse. The same fuse for the lamps supplies power to the relay coil. Check the connection at pin 87 and 30 at the relay socket.

There is a "joint connector" in the PDC. Basically it's a means of joining the feeds to all the various lights, front and rear.

 

Yes the headlights and everything else works just not the rear running lights. Previous owner put in a tow package that looks to be professionally installed. Starting to wonder if it has something to do with it but it is a separate wire run the same path as the rear lights conduit that splits and runs into both connectors for the rear lights

 

I would think if the pdc was bad there would be other issues. Are those pins the supply and ground for the lights?

 

Forget about the headlights. They are on an entirely different circuit. Are the front marker lights working?

The joint connector in the PDC is the supply. The chassis is the ground.

Odds are VERY good your tow package is the culprit. They had to tap in somewhere.

 

Their are no marker lights. Sorry, had to look up what that was😑. Literally every light function works except the rear running lights.

 

Yes, there are front marker lights. They are in the amber part around the headlights - where the turn signals are. I take it they DO NOT work either. How about the license plate lights?

Since you hear the relay click, check for power at pins 86 and 30. They both should always be hot as they are fed directly off the battery by fuse #4 (20 amp).

Pin 87 is the feed to the lights. Maybe try making up a jumper wire.

 

Did you happen to hook up a trailer before this happened?