Tail lights on at their own will, key is out of ignition???

[Mark Craig]

Ok members got a good one for you. I have a 2007 3500 Mega with a 6. 7L and 68 trans. In the last week (at 61,000. 0 miles) the tail lights have decided to turn on and stay on for odd amounts of time. Anywhere from 1 - 30 minutes. The will flicker sometimes when they are on as well.



It happens after you shut down, key removed and go inside. Some days it seems to happen more often than others, but it happens all the time. Glad we have dual batteries or I am sure by now I would have been looking for a jump start.



Any help is appreciated. So far independent and dealer techs have come up with zilch!



Mark @ DPPI

 

[NIsaacs]

I would guess a bad light switch. In order for the tail lights to get power, it would have to pass through the light switch. I assume you are sure it is not brake lights?



Nick

 

[Delrayz]

Light switch is an input for the front control module... . start at the FCM. . seen this before and the only fix was a new module. . all output can be activated with the dealers scanner$$$$$$... . Like my girl says. . go big or go home!!

 

[Mark Craig]

Been there and it's OK. Pretty much a mystery so far???



Mark @ DPPI

 

[rbattelle]

When you say tail lights, do you mean the brake lights or the running lights? Or both?

If it's the brake lights, try disconnecting the brake pedal switch next time it happens, just as a place to start.

I'd have guessed FCM like Delrayz says, so this is a real stumper.

I wouldn't be surprised if it turns out to be a bad TIPM - they seem to be a bit touchy.

Ryan

 

[Wingate]

brake light switch????... We've had this problem with our C4500 Chevys. Happen to look outside in the middle of the night and see the brake lights on, sometimes flickering on and off... .

 

[DennyDay]

Had some problems with my '06 with the switch hanging up in the on position. Got out of the truck several times to find the brake lights on. Lifted up on the pedel and they shut off. Taped a shim on the peddle and fixed the problem

 

[JFought]

***mine is better!!!!!!! same senerio but only running lights on on the driver side frt and back!!!!! that's it!! i even took a pic and after it fixed its self the dealer says they don't know why. .

 

[cclark746]

didnt realize how common the old brake pedal hanging up was on the 06

 

[Bigiron]

I've had the same problem before with my 97 dually. It was the plug for the trailer light on the back of the truck. It was shorting out between the wires in the actual plug itself. I disconnected the wires one by one and found the guilty wire. I can't take all the credit for the fix, I have a co-worker that was a mechanic that pointed me in that direction. Good Luck.

 

[Bigiron]

One more bit of info, mine was feeding from the BATT wire to the tail lights.

 

[tmccarty]

I will check the 7 way plug out and let you all know what i find, already replaced the switch

 

[DogramTD]

My headlights did the same thing... It was the IC... 3rd one and still having problems. Good luck