I have an FG falcon XT.

Everytime I press the breaks. the auto headlight comes on, but its only the parkers. I also notice the rea driving lights turn on as well. Including the brakes. I cannot drive the car at night beacuse of this. if I turn my lights on cruise control wont work either. I think the brake lights are constantly on with the parkers.

Any help would be appreciated.

replace both tail light globes

IF you have replaced them previously .... they 'might' have been refitted wrong. take care when fitting globes due to the pins on the base.