Into Park or out of Park?
You don't mention what year of Mercury Grand Marquis but the owners manual will explain what to do if the transmission gear shift lever will not shift out of ( P / PARK ) with the brake pedal depressed ( it has what Ford calls the " brake shift interlock " ) As of August 6 , 2012 you can still view the Mercury Grand Marquis owners manual online ( back to the 1996 model ) at : www . motorcraft service . com ( no spaces ) Click on Owner Guides
check your brake lights if they not worhing replace fuse or brake light switch
It could be a fuse. If the brake lights do not turn on when you press the brake pedal check your fuses under your dash.
Here is a handy trick to bypass that problem. Once running, turn the key slightly pass the start position. You don't have to go so far as to here your starter grinding. As you are doing this you should be trying to shift out of park. Sorry I can't guide your fix.
APPLY BRAKES AND SEE IF BRAKE LIGHTS COME ON. IF NO BRAKE LIGHTS, REPLACE THE BRAKE LIGHT SWITCH LOCATED ON THE BRAKE PEDAL ARM AND THIS SHOULD ALLOW YOU TO SHIFT OUT OF PARK. IF THAT BRAKE LIGHT SWITCH IS BROKE, YOU WON'T BE ABLE TO GET IT OUT OF PARK
Just turn the key to the first position, ( not on ) and then you will be able to shift to neutral and start the car from there. Have the fuses checked and check the shifter sensor on the brake pedal.
Sounds like a bad Brake Light Switch. It's located on the steering column.
If it works like the one in my '94To set it: in park press the pedal to the floor.To release it press the regular break pedal and shift out of park.
Check the fuses- Shift interlock is the same circuit as brake lights. As a temporary measure - try to turn the key to 1st (unlock) position shift to neutral to start vehicle and then shift to Drive.
Stuck in Park? Check to see if the stop lights are working - shift interlock is the same circuit - check the stop light fuse Try to turnthe key to 1st (unlock) position, shift to neutral start vehicle and the shift to Drive
Find the switch attached to the brake pedal for the shift interlock and jump the two wires together. Be careful not to disconnect the brake light switch
THE BRAKE LIGHT SWITCH IS NOT PUTTING OUT BATTERY WHENEVER THE BRAKE PEDAL IS PUSHED DOWN. CHECK TO SEE IF BRAKE LIGHTS COME ON WHEN BRAKE PEDAL IS PUSHED DOWN. IF BRAKE LIGHTS COME ON, THEN YOU SHOULD BE ABLE TO SHIFT IT OUT OF PARK. IF NO BRAKE LIGHTS, THEN IT WON'T SHIFT OUT OF PARK. IF THIS IS THE CASE, THEN REPLACE BRAKE LIGHT SWITCH.