Red/Black Wire Problem

From E30 Zone Wiki

This is a problem that effects the connections in the door pillar and brings all sorts of gremlins to the central locking and all circuits going through the door'...recommended by the zone electrics guru Brian Moore and re written by daimlerman. This guide has also been copied in "Central Locking Problems " in this wiki as well

Red/black wire mod to central locking

Why do we do it?

BMW use a logical wiring system where all red wires are constantly live.

The red/black wire makes a loop into,and out of,the driver's door via the A pillar socket.This is known to cause corrosion and general mayham both within the socket and to other wiring in the area.

The fix is to eliminate the live loop through the door.

How?

Remove battery earth lead.

Remove the driver's side kick panel/speaker cover.(one screw)

Remove the speaker(three more screws)

Reach into the hole and pull the hank of harness going to the A pillar socket into view(try not to pull the socket out if possible)

Locate and cut the red/black wires,saloons have two,cabbies have three.

Solder and heatshrink the harness ends together,insulate the ends going to the socket.

Replace speaker and cover.

Re-connect battery.