2nd Gen Non-Engine/Transmission Parking lights are on

[mfburns]

At work today a fellow worker said I left my lights on. Strange since I didn't use them today on my way to work. Sure enough the parking lights, front and back are on. I pull and check fuzes, pull and push the light switch and still the lights are on. Finally I disconnect the ground on the driver side battery and the parking lights finally go out but the under hood lamp remained lit while the hood was open. When I fueled up 10 miles from work I did not notice the lights being on and I washed them, front and rear.



Its a 94 2WD 2500 all original, 220K miles



Is this a light switch problem or something else????



Any ideas

 

[khalsey]

Maybe trailer connector has corrosion and is shorting between parking lights and hot wire.

 

[terrywerm]

If I recall correctly, the second gens all have fused power to the light bulbs all the time and the headlight switch and turn and brake switches provide the ground. I know they are that way on the 01's not sure on the 94's.



Try looking for a ground on one of the wires for your parking lights, or for the license plate lamps, as they are famous for breaking/corroding off. If the ground is broken off, it may be touching metal someplace and providing a ground for the circuit.



I had a similar wierd incident a couple of weeks ago. One of my kids came in and said that my headlights were flashing on and off, but erratically, not in any certain pattern. I checked it out and sure enough, they would come on, then go off for completely random periods of time, completely on their own



It was in the evening and fairly cold, temps down near zero, and it was breezy too. I didn't feel too much like screwing around with this new mystery, but decided that I had better. Those of you that have installed the aftermarket headlight harness from Summit Racing will want to pay attention here!



I installed one of those harnesses a couple years ago to remove my headlight load from the headlight and dimmer switches, which resolved an occasional problem that I was having with the dimmer switch (another story for another time). With that harness, the new headlight relays are triggered by the circuit for the left headlight, and the original plug for the right headlight is disconnected. Well, if you look closely at that unused plug, you will see that the little metal contacts actually stick out past the end of the plug just a tiny bit. The way my plug was hanging, the contact for the right high beam was just rubbing on the paint at the bottom of the inside of the fender, eventually wearing through the paint and completing a ground for the high beams. This ground went back through the multifunction switch and enabled the high beam headlamp relay for the harness to energize, turning on both headlights. The fix was easy once I found it: cover the unused plug with e-tape and tie wrap it in place where it can't rub on anything.



During the trouble shooting process I consulted the wiring diagram in my shop manual and that is when I found out that the switches actually just switch the ground for the lights.