Nissan Repair: Mercury Villager, mercury villager, trailer harness

Question
I have a 1996 mercury villager, the brake lights stay on when the head lights are on. The brake lights work with the head lights off but light up the dash and parking lights when the brake pedal is pushed.  I have replaced the head light switch and brake switch.  Now I am at a loss, any suggestions?

Answer
If you have a trailer harness there could be a short in the harness backfeeding power.  Also, check the bulbs in the back to see if the sockets are shorting as this is an area where current can backfeed.  I have seen bulbs where the filament in a dual type bulb shorts and power backfeeds.