As far as i now subarus dont need turbo timers as there air and oil cooled, i have one fitted for warming up before i leave work.
1.DISCONNECT BATTERY.
2.TAKE DOWN COWLING FROM UNDER STEERING WHEEL
3.LOCATE IGNITION WIRES(USUALLY TAPED TOGHETER)
4.SPLICE WIRES,GET MULITMETER LOOK FOR CONSTANT LIVE 12VOLTS ,LOOK FOR IGNITION SHOULD READ CONSTANT WHEN IGNITION OFF AND 12VOLTS WHEN ON
5.Earth FIND A GOOD EARTHING SPOT SOMEWHERE ON THE BODY IS USUALLY BEST
6.RUN HANDBRAKE WIRE UNDER CARPET TILL YOU REACH HANDBRAKE YOU SHOULD SEE EITHER PURPLE OR WHITE WIRE SPLICE IN,
7.RECONNECT BATTERY,AND CHECK THE TIMER IS DOING ITS JOB TURNING OFF THE ENGINE WITHOUT KEY BY PUTTING HANDBRAKE DOWN,AND TURNING OFF AFTER SET TIME
I usually solder the connections,our you can just tape them,make sure there taped and making a good connection.