This is how to replace a brake light switch on a 1998 Isuzu Trooper. If the brake light switch is not working properly, the transmission will not shift out of park. My Trooper would not shift out of park and I knew the transmission was working properly so I had to do some research online. I Learned the brake light switch controlled a solenoid in the transmission shifter mechanism that moves a piece of metal preventing the driver from shifting out of park.
Horrible video no help