Ok. Having an odd issue with my truck. It is a 95 Dodge Ram 1500 4x4 Single Cab with the 5.9l magnum V8. A few months ago the truck suddenly started running rough like it’s misfiring on 1 cylinder. Haven’t gotten around to working on it until now but was thinking I just had a distributor or plug wire issue. Started my truck a few days ago and it’s still running rough which was expected. I did notice though that my taillights/license plate lights are on even though they aren’t turned on at the switch. If I turn on the running lights then the truck stalls out. Also stalls out if I engage the brake lights. I checked the grounds to the chassis and to the engine and all tested good. Alternator is putting out about 14.3 volts as well. I pulled the fuses for the running lights and brake lights but taillights/license plate lights are still on. I also noticed they are only on when the truck is running. Not when the ignition switch is in the on/run position. Hoping somebody can point me in the right direction to where to look.
Thanks in advance!

 

These trucks melted the headlight switch. Fix is replacing the switch and installing relays from LMC or Daniel Stern. I would look over the grounds again, under the dash too. Check the harnesses behind the engine for rubbing or melting.

 

Thank you for your input. Would the headlight switch still be the issue even if I pulled the fuses under the hood relating to all of the the lights? Is there even power going to the switch if the fuses are out? When the engine isn’t running then the lights act normal but if the engine is running then the taillights are on but the truck dies if any other power goes to them(brakes or running lights). I did pull the fuse for just the running lights and while the engine is running the headlights come on and function just fine. Both brights and dims function perfectly as long as the running lights aren’t on while the engine is running. It seems like the engine is somehow bleeding power to the taillights circuit but I’m not sure how. I’ll buy the headlight switch and change it out just to see if that fixes the issue though. I’ll also check the grounds under the dash.
Thanks!

 

It will be melted if there's a problem. I guess I would look over all the harnesses and look if they're rubbed through. I wonder if wires could be rubbed through in the steering column or under the dash.