My Running Lights

[Canada_CT230]

I have a 1999 Dodge Dakota and pull a 2010 KZ CL164 travel trailer. Currently on a trip and my running lights on the trailer are not working. Stop lights, turn lights, 12V power feed and brake controller all work.

Here is what I've done so far...

1) Replaced the 7-pin plug on the truck. Trimming back any signs of corrosion at the wire ends.

2) Tested the trailer running lights from a separate 12V battery with jumper cable into the 7-pin of trailer. Running lights work that way. Now I don't suspect the trailer. Trailer only has about 3000 miles on it.

3) Tested all pins on truck 7-pin. I get 11.xx volts on the 12V power feed, I get variable voltage on the brake controller (working) and I get 11.xx volts on the running lights pin.

4) I continuity tested ALL fuses in the trailer and checked the junction boxes and secured all wire nuts.

5) I tested ALL fuses in the truck and also swapped some relays under the hood for the running lamp / towing circuits.

6) Cleaned the terminals in the trailer 7-pin.

How the BLEEPing heck do you get power at the plug and still no running lights? And the stop, turn signals and brake controller work.

I am plum out of ideas. I am going tomorrow morning to my old employers shop to see if the heavy duty mechanic there has any ideas. Cause I don't.

 

[jeffsw6]

Re: My ****BLEEPING*** Running Lights

Were any truck fuses blown before you replaced them?

The first thing I think you should do is get some 12V lamps and re-test the truck connection to make sure it works under a real load, not just under the fraction-of-an-amp load presented by your VOM. If it can't light up a few amps worth of test lamps between the truck's running light and ground pins, the truck has a faulty wire or relay.

I think the above test will show that your truck is unable to supply sufficient current for some reason and at least you will then know to start examining the truck more carefully.

If that doesn't reveal anything, I think you should use a VOM that has an amp meter function (or use the ohm meter and do some arithmetic) to determine the current draw of the trailer's running light circuit. With my ~$50 Home Depot VOM, the way I would do this is hook the trailer ground to the truck (or 12V battery) ground using a spare length of wire 12ga or so, and then put one VOM probe into the trailer connector's running light socket, and the other probe into the truck (or 12V battery) pin. If it shows a large figure like 10A then something is probably wrong with the trailer, like a short or some accessory drawing a lot of current from the running light bus. If it shows a couple of amps I would say that's normal. Nearly 0 amps, back to wtf territory.

I would do the above test first with the truck's connector and second with the 12V test battery.

It could also be that the trailer 7-pin is screwed up and doesn't mate with the truck right just on that pole, but your probe or test wire can make good contact with it. Stranger things have happened.

 

[Diamondpilot]

Hit the nail on the head above. Its either a current issue or you are simply not making a connection on that pole. Try jumping that pole from the truck to the trailer.

Now lets talk about wire nuts and automotive or trailer wiring????

Chris

 

[Canada_CT230]

Re: My ****BLEEPING*** Running Lights

No fuses were blown.

OK, that may be an idea. Maybe still a bad ground / wire somewhere that doesn't let me get any amp draw...I'll investigate further on that.

I have jumped the wire...eliminating the 7-pin plug. It is not a loose or mis-connection there.

I'll report more after I get it to a shop with more tools.

 

[Redneck in training]

Re: My ****BLEEPING*** Running Lights

Voltmeters are high impedance devices. Vmeter draws minuscule current so it might measure 12V even over bad connection. Better way is to use a light bulb. You can buy light bulb tester it in auto parts or improvise one from a 15W light bulb and few pieces of wire. Since it will draw over 1 amp the voltage across bad connection will drop and the bulb will not light up or just glow red. You can also connect you Vmeter parallel to the bulb tester.

 

[jeffsw6]

Re: My ****BLEEPING*** Running Lights

I don't think you have a ground problem. If that was the case your other electrical loads would be affected.

 

[Hilltop Hillbilly]

Re: My ****BLEEPING*** Running Lights

I have a 1999 Dodge Dakota and pull a 2010 KZ CL164 travel trailer. Currently on a trip and my running lights on the trailer are not working. Stop lights, turn lights, 12V power feed and brake controller all work.

<snip>

How the BLEEPing heck do you get power at the plug and still no running lights? And the stop, turn signals and brake controller work.

I just went through a similar ordeal with a 2004 Dodge Ram 2500. Brake and turn lights worked fine, but running lights were dead. However they were dead on the truck too. Spent hours testing fuses and everything else under the sun.

Turned out to be a fault in the fuse box itself (under the hood). Apparently the fuse box design allowed water to collect (and corrode) the wiring in a sealed part of the harness leaving the fuse box. Had to replace the whole entire assembly to get my running lights back ($600, ouch!).


HH

 

[George2615]

Re: My ****BLEEPING*** Running Lights

I had a similar problem with my travel trailer. None of the running lights (marker lamps) were working. Brakes, turn, and park lights worked. Mine turned out to be poor connections on each light. My trailer sits, sometimes for several years at a time, then when I wanted to use it I had to take the cover off each lamp and clean the contacts. I tested each bulb as well. My marker lamps only have one wire feeding them from the parking light circuit as they are grounded through the trailer aluminum skin. Apparently some oxidation set in causing poor or no ground.
Can't help much since you already know your trailer running lights work using a jumper wire to the trailer plug. If you have running light power at the truck plug end but not when you plug the trailer in it sounds like the trailer plug connection is bad.

 

[crazyal]

Re: My ****BLEEPING*** Running Lights

Voltmeters are high impedance devices. Vmeter draws minuscule current so it might measure 12V even over bad connection. Better way is to use a light bulb. You can buy light bulb tester it in auto parts or improvise one from a 15W light bulb and few pieces of wire. Since it will draw over 1 amp the voltage across bad connection will drop and the bulb will not light up or just glow red. You can also connect you Vmeter parallel to the bulb tester.

Most of the light "bulb" testers I've seen sold today are LEDs. Not the good old style that could test load as well as voltage, too bad.

 

[Garybake]

I wold be looking at the running light grounds. The lowest amperage draw grounded by a mounting screw to painted trim that after a couple seasons turn green with corrosion at screw(or bulb holder). When this happens to brake/turn signal lights voltage seeks ground through lower resitance tailight fillament and they are not bright but come on dim. Also only takes a couple minutes to just file ground connections clean at 7 pin harness to trailer and gives you peace of mind that it is not trying to ground through hitch or saftey chains.