I thought perhaps this would be of interest regards Reversing Lights.
I don't know if its the same everywhere but presume so:
On RHD vehicles the left rear bumper bar light is the white reverse light - its quite weak.
The right hand light is all red and is a rear Fog Light.
On LHD vehicles, the above is reversed.
I wanted stronger reverse lights, so I hunted on the internet and found a overseas Right hand reverse light and ordered it.
I also purchased two LED reverse lamps - about 1800 Lumens each but less that 20 watts combined.
My Reverse lamp has a T15 wedge. The Fog side has a large T30 wedge, but that didn't matter because the new light arrived with its own T15 wedge fitting. I very slightly modified the two pin plug of the cars harness as it has a very small stop block to insure direction which is easily cut off and the clip that holds it in place insures correct insertion anyway.
So at that point of time I have both bumper bar lights as red top and white (reverse) bottom halves, but still operating as a separate reverse lamp and fog lamp.
And both quite bright - so much better in the camera or looking over my shoulder for reversing at night.
The Reverse light wiring is Blue (L) and Black (B),
The Fog light wiring is Green (LG) and Black (B).
These four coloured wires appear in their own connector in behind the rear bumper bar cover a little above a large multi-pin connector which are the rear bumper parking sensors.
Its easier to get to the connector by taking the bumper bar cover off but that is a longer more involved task, so I wrestled with a small screwdriver lying under the back and disconnected both connectors which allowed me easily enough length to pull down below the bumper bar.
Then I carefully unwound the factory loom back about 40mm exposing the two coloured wires.
I didn't cut them but carefully peeled back the blue wire up at the loom and and the green wire closer to the plug end. I then soldered in a 5 amp power diode* with direction allowed from blue to green, but prevented from green to blue.
Then I refolded the split plastic tube back over the wires and diode and wrapped tightly in stretch tape that sticks to itself and forms a waterproof bond. It looks completely factory.
Entire job took about 2 hours but that included wire tracing and associated sleuthing.
*So this may possibly not be necessary and the two colours could simply be connected.
The two reasons I installed the diode was that -
1) the Reverse lamp is lit by a relay (no problem) but the fog light is lit by a Field Effect Transistor (FET) inside the ETACS-ECU and I didn't want any chance of a reverse voltage damaging it or any other components.
2) it would operate both the rear bumper lights as Reverse lights (desired) but also both of them as fog lights (not ideal).
So the diode allows the selection of reverse gear to light both rear lights (3600 lumens out the back) but will only operate the single RH Fog light when the Fog lights are initiated.
Admittedly, the rear fog is now 1800 lumens and its white, but to be honest - I've never in memory needed or used fog lights in Australia anyway.
On my BMW I actually wired via a jump switch the front Fog lights to come on with the high beam because they spilt heaps of wide white light in front of the car and off to the sides, and filled a void of about 3 metres in front of the car left by the high beams.
I don't know if its the same everywhere but presume so:
On RHD vehicles the left rear bumper bar light is the white reverse light - its quite weak.
The right hand light is all red and is a rear Fog Light.
On LHD vehicles, the above is reversed.
I wanted stronger reverse lights, so I hunted on the internet and found a overseas Right hand reverse light and ordered it.
I also purchased two LED reverse lamps - about 1800 Lumens each but less that 20 watts combined.
My Reverse lamp has a T15 wedge. The Fog side has a large T30 wedge, but that didn't matter because the new light arrived with its own T15 wedge fitting. I very slightly modified the two pin plug of the cars harness as it has a very small stop block to insure direction which is easily cut off and the clip that holds it in place insures correct insertion anyway.
So at that point of time I have both bumper bar lights as red top and white (reverse) bottom halves, but still operating as a separate reverse lamp and fog lamp.
And both quite bright - so much better in the camera or looking over my shoulder for reversing at night.
The Reverse light wiring is Blue (L) and Black (B),
The Fog light wiring is Green (LG) and Black (B).
These four coloured wires appear in their own connector in behind the rear bumper bar cover a little above a large multi-pin connector which are the rear bumper parking sensors.
Its easier to get to the connector by taking the bumper bar cover off but that is a longer more involved task, so I wrestled with a small screwdriver lying under the back and disconnected both connectors which allowed me easily enough length to pull down below the bumper bar.
Then I carefully unwound the factory loom back about 40mm exposing the two coloured wires.
I didn't cut them but carefully peeled back the blue wire up at the loom and and the green wire closer to the plug end. I then soldered in a 5 amp power diode* with direction allowed from blue to green, but prevented from green to blue.
Then I refolded the split plastic tube back over the wires and diode and wrapped tightly in stretch tape that sticks to itself and forms a waterproof bond. It looks completely factory.
Entire job took about 2 hours but that included wire tracing and associated sleuthing.
*So this may possibly not be necessary and the two colours could simply be connected.
The two reasons I installed the diode was that -
1) the Reverse lamp is lit by a relay (no problem) but the fog light is lit by a Field Effect Transistor (FET) inside the ETACS-ECU and I didn't want any chance of a reverse voltage damaging it or any other components.
2) it would operate both the rear bumper lights as Reverse lights (desired) but also both of them as fog lights (not ideal).
So the diode allows the selection of reverse gear to light both rear lights (3600 lumens out the back) but will only operate the single RH Fog light when the Fog lights are initiated.
Admittedly, the rear fog is now 1800 lumens and its white, but to be honest - I've never in memory needed or used fog lights in Australia anyway.
On my BMW I actually wired via a jump switch the front Fog lights to come on with the high beam because they spilt heaps of wide white light in front of the car and off to the sides, and filled a void of about 3 metres in front of the car left by the high beams.
