89 Crown Vic brake lights work when park, not when moving.

park brake light is come on when parking brake is set position. if light stays on when released the switch is located on the parking brake is defective and needs to be replaced, generally not to difficult to accomplish this replacement

Check the wires going to the brake light switch they brake often and check the switch. Step on the brakes first and make sure you have lights if not proceed to switch and wires at brake pedal

THE BRAKE SWITCH RELEASES THE SHIFTER FROM PARK, ONE FOR PEDAL RELEASE AND ONE FOR BRAKE LIGHTS?

All 2000 and up vehicles utilize a Solenoid which is powered by depressing the Brake Pedal to allow the Shift Lever to be move from Park to any other position. Is the Shift Lever located on the Steering Column or the Floor? In either case typically the Solenoids used by Ford do occasionally go bad. I highly recommend having a certified technician replace the solenoid.

The sensor on the brake pedal is not working. The brake pedal must be pushed before the shift level will release and allow shifting. If you are holding in the brake but it is not letting you shift, the brake activation switch is not working properly and, therefore, not allowing you to shift out of park.

It is also possible that the fuse for the brake lights is out and not activating the switch but this is less likely.

Good luck,

-Mark

ok you can have a few things wrong. First have some one step on brake pedal see if brake lights come on. If not these vehicles were bad about the wires braking to the brake light switch. After check ing lights and you have found the are operating correctly, try turning igintion key cylinder to first notch just before dash lights come on, now see if you can shift out of park if so the shift interlock solienod on back of column is bad. Lastly if the sifter is really loose they are two 30 torx screws on the back of the column hold the bracket to the shift cable, if that comes off or loose you can not shift as well. Hope this helps if so please vote thank you

Check all the bulbs at tail end for parking and brakes, test grounds and harness for trailer. Check fuses. clean batery terminals, Re instal head light swich properly and make sure all wires conect.
Vitally

when you depres the brake pedal do yoiu hear a clicking noise in the steering column? (this noise would be a sign of the shift interlock solenoid functioning)? are all of the brake light bulbs working? (it wont let you shift without all brake bulbs working)....you can overide this shift feature by turning key to on position, without starting vehicle, shift into neutral, then into your desired gear. i hope this helpos your some! good luck!

check under the dash st the brake pedal,there is a brake light switch which is tied into the cruise control,you could try unplugging that and see if it fixes the problem(remember you will have no brake lights while it's unhooked) if the problem is gone replace the switch.

push the brake and see if brake lights are working if not then replace the brake light switch.