My 84 pickup has power running to the taillights and running lights constantly. I try turning the switch and they stay on. The only thing that works for the switch is headlights. The only way to turn taillights off and running lights is to turn the vehicle off. I'm stumped. The only thing the dimmer does is dim them real low( imagine that) . any ideas? If I have to I'll run them constantly. Since new vehicles these days have running lights even during the day. I just can't figure out why they are on constantly an its bugging the hell out of me. Any input would be appreciated!

 

The parking light circuit is being completed through a path other than the switch.

If accessory lights were ever installed, with the relay incorrectly wired so they provided power to the light circuit, then that could be it.

Test light is your friend! Get probing! Lol

 

Quite possible the last owner wired them like that

It should be pretty easy to find .

The tail light relay is getting system voltage some how .