There are a variety of harnesses available, these are the colors from my harness, and your harness may vary. Special thanks to Bob Voller for his help in supplying the following wiring connections, without his help I would not have been able to complete this conversion.

There should be two black plugs located next to the main ECU plug. These plugs should contain the following wires. As described above, your harness may contain the fuel quality relay in addition to these two plugs. Further still, your harness may have a connector that is covered with a weather tight cap, this is for the on-board diagnostics.

Grn/blk wire to ignition 12 volts
Blk ground
Pink/white wire to both fuel pumps
Pink second fuel pump - terminate
Grey/yellow A/C input
Blue/yellow test button - normally open switch, ground other side of switch
Blue/red check engine light - any 12-volt lamp will work
Purple/black leave open
Purple leave open
Purple/white ground
White/red to diagnostic connector
Brown or white Tach signal

3 Heavy red wires wire to 12 volt constant, place 30-amp fuse between battery and connections

The following is a description of the remaining wires on the harness and their functions.

There are 3 main relays and 1 Diode relay.

Relay identification

1. Main relay
pin 30 - heavy red 12+ constant
pin 85 - Blk - Ground on Cam cover
pin 86 - two small grn/blk
pin 87 - two medium one small grn/blk

2. Second relay
pin 30 - two small green black
pin 85 - yellow/red
pin 86 - red/blue
pin 87 - yellow/black

3. Motronic Relay
pin 30 - heavy red
pin 85 - two black
pin 86 - grn/black
pin 87 - two red one red/blk one orange

4. Third Relay
pin 30 - grn/blk and blue/yellow
pin 85 - gray/black
pin 86 - red/blk
pin 87 - two white pink, or one white pink one pink.

Relay functions

1. Main relay - Supplies power to both coil packs and timing variator relay
2. Timing variator relay - activates variable cam
3. Motronic Relay - supplies power to fuel injectors, idle control, ECU
4. Fuel pump relay - provides activation of fuel pump(s).

You can locate the fuel pump wires in two places on a Bosch spider. The in-tank pump can be traced to the wiring harness behind the drivers seat, the under car pump can be located behind the passengers seat, both wires are pink. Connect these to the pink/white wire of the fuel pump relay.

The switched 12 volt source can be located on the passenger side of the car underneath the dash, there is a connector located there that has two grn/blk wires coming out of it, connect the grn/blk wire from the Motronic harness to this connection.

For the Tach, connect the white or brown wire to the white wire in the engine compartment located next to the original coil location.