driver's side , inside the car, near the parking brake.
I believe the obd port is located by the parking brake and just above it.
adjust the shoes
The red " BRAKE " light in your dash means that either your parking brake is on or the BRAKE FLUID LEVEL in your brake master cylinder in the engine compartment is LOW
Adjust or replace the stoplight switch at the upper end of the brake pedal under dash area
Fuse location 8 (20 amp) in the instrument panel fuse box, drivers side by the parking brake.
with tools
DOT 3
grand marquis
According to the 1996 Mercury Grand Marquis Owner Guide : ( DOT 3 brake fluid , meeting Ford specification ESA-M6C25-A )
Check the brake light switch ,on the brake pedal. Might need adjusting.
Could be the tires, or your front brake rotors