I believe that wire is for the parking brake. I have a newer HKS turbo timer and i believe thats what it is connected to. I can look in a couple of hours and then i'll reply. You are lucky to find treasures from the last owner. what i found from the last owner on my subi: front and rear diff's were shot, 1st/2nd gears were shot, clutch problems. and then one day i looked for the car jack and found chick sandals jammed in there, which explains the first 5 problems i had before.