Ok I was looking at the three harnesses underneath the dash on the left side and the middle harness which has a blue harness plug has a grey wire with a brown dot on it is this the parking brake wire? I hate wiring diagrams and electronics by the way! lol
My Haynes was left in my Grandson's 84, and the FSM I have doesn't give color codes. That parking brake switch is one of the simplest circuits in the car. On one side of the switch is ground, then a diode and then the dash light that shows the brake is on. If you are trying to apply power to your turbo timer only when the parking brake is applied, the wire would be spliced in between the diode and the light. Put a voltmeter probe on the wire you think is the right one, turn on the ignition switch, pull the parking brake on and the meter should go from zero to 12 volts.
If you need 12v whenever the ignition switch is on, any switched wire would do the job. Never having installed a timer, I have no idea what the instructions read and why they would specify that particular wire.
The parking brake switch wire can probably be accessed in the wire bundle leading to the dash indicator lights.
Thanks notdeadyet! the reason I have to use that piticular wire is becuase the turbo timer will keep the engine running after I shut it off and the turbo timer wont engage if the parking brake isn't engaged.