Nissan Repair: 97 nissan truck light problems, trailer wiring harness, nissan truck

Question
i have a 97 nissan 4wd pick up and sometimes when i put on brakes the instrument panel lights up and the parkin lights come on when they arent turned on and my 3rd brake light stays on no matter what. what could be the problem?

Answer
Justin,

Power from the brake lights is backfeeding through the master switch.  The instrument lights is the clue here since this is the only place the wires come in close proximity.  I would think the headlight (Master Switch) is shorting internally.  Now, no one has screwed with the rear wiring like as in a trailer wiring harness being cut into and spliced to the factory harness?  If this is the case, check to make sure there are no shorted wires in the harness first.