I have a 2006 Dodge Ram 2500 diesel truck that has the reverse or backup lights on whenever the running lights are turned on. A Dodge service man suggested that the problem was the Neutral safety switch, which I replaced but it had no effect. I've seen many posts reguarding older trucks with a separate reverse light switch, but my tranny doesn't seem to have one. Any ideas?

 

Do you have factory or aftermarket tow harness? I'm thinkig maybe a wire is crossed?

I do know that the 2006 Rams had problems wth the tipm in regards to the directionals when in tow and would cause shorting out/blowing fuses. New tipm for '06 is $600, but that should not be your problem.
If you don't find the problem, you could always install a switch inline to turn them off. Driver side firewall behind the battery and ABS module, white wire w/ltgreen stripe is the reverse wire uried in the wire conduit. You could cut it and install a switch incab. Obvioulsy this is a last resort fix, but it will work. You could install a relay instead of a switch that will turn them on/off and override the real problem...

Go over to the diesel section and take a look around in regards to the reverse light switch(I dont think you have one)

 

Thanks Dirty Dog. The Tow harness is factory original. My temporary fix has been to pull the lightbulbs out, after I got pulled over by a policeman, but fortunately only got a warning. I thought about using some red tape, but the backup lights are pretty bright, so it looked like I was braking all the time.

 

Have you thought of replacing the boards the bulbs plug into

 

No electronic boards on the 2007 that I am aware of. They are just simple ordinary plugs like most vehicles have. If you are referring to the plugs themselves...They can't just provide power by themselves. If there was somekind of short in a single plug, the bulb would fail to illuminate.

Even if there were electronic boards, you should unplug all connectors to eliminate any possible shortings and then probe the wires that are for the reverse lights. If after all of that, there is still power on the reverse light lead, then the problem lies elsewhere. If there is no power on the reverse leads when the board(light) is unhooked, then it would clearly be the board that is the problem.

 

most of these trucks have stuff triggered by grounding thru a resistor maybe the resistor is bad. not sure how you would go about checking this
download the service manuals from weedahoe and follow the wires lol