Part 14: Vehicle wiring harness

Follow the QPEng P'n'P OEM kit installation guide for detailed instructions.

Some fitting work is necessary for the installation of the engine electrics box to the Mk2 inner wing.

Otherwise all connections should be straight forward

TFSI engine connections

Connect the 14-way connector on the QPEng vehicle harness to the corresponding connector on the engine harness.

Connect Wide-band lambda sensor

Connect MAF

Connect main engine electrics box connections (26-way and 40-way)

Connect Aux coolant pump and sensor 4-way

Connect alternator feed to vehicle blue wire

Inside the car, connect throttle pedal, brake switch, CAN gateway

Connect ECU connectors

Battery and alternator wiring

Connect the original Mk5 12v accessory wire to the engine electrics box using the M8 bus-bar and fuse.

Connect the small blue alternator wire from the Mk1/2/3 to the small blue wire on the QPEng vehicle harness.

Connect the original Mk5 12v supply harness from the starter post to the battery and engine electrics box

Main Vehicle interface

Connect the red/black Tacho wire from the QPEng harness to the red/black wire that used to go to the original ignition coil.

Connect the black ignition wire from the QPEng harness to the black wire that used to go to the original ignition coil.

Connect the Fuel pump relay wire from the QPEng harness to the corresponding connection on the vehicle – in this case by Digifant 5-way connector

Interior harness

Connect the 12 way connector to the QPEng Vehicle ECU Harness and secure the connector to the bodywork using cable ties.

Route the wiring to the pedal taking great care to ensure it is well secured, cannot chafe and is well away from pedals and steering column.

Install the CAN gateway unit onto the back of the lower stowage tray and route the wiring to it, again ensuring that it can’t get caught or chafe.

Route the OBDII connector to suitable position and secure the wiring.

and install the connector.

Connect the 2 x spade connectors on the interior harness to the original brake light switch wiring.

Recheck all the wiring and the 12 way connector to ensure they are fully secured and can’t chafe, become caught, or trapped.

Conversion complete!