Rear Fog Mod

[teeps]

I have recently been posted to Germany, and taken Zara with me. As has already been mentioned somewhere on this site, the lighting test that is mandatory for all British forces based in Germany is actually more stringent than the German MOT equivalent (i.e. flattened front beams will not pass, necessitating forking out £700 for a new set of LHD xenons, whereas flattened beams will pass the TUV). Another area that requires changing is the rear fog light - it needs to be on the left hand side (or drivers side, for a LHD car). I've seen on here various posts about swapping bulbs over and trying to get both to work, but my question is this:

What pins in the rear lighting harness go to the RH fog?

My aim is to run a wire from R to L in the boot, under the trim and remove the R bulb, so that when pressed, the L fog comes on instead of the R.

 

[VvrooomM]

I think that area is used under very hard ABS braking to display extra bright lights. It might not be as easy as you think without a recode.

 

[teeps]

But surely if the fog light on the right hand side can be switched on and off manually whilst still being used for the brake force display, and the bulb is present on the left hand side, running a wire from right to left will enable the left hand light to be effectively switched on or off manually. I'm aware that removing the right bulb will probably trip the dash warning light, however for the sake of passing the test...

 

[teeps]

It was cold.
It was dark.
I was scared...

But I cracked on and did it anyway. I have now got two working rear fogs (only for the time being to see if it could be done - tomorrow I'll be removing the right bulb so that I meet the rules and regs on the continent). It didn't require any re-coding or soldering - just 1.5m of 12V wire, a flat head and a cross head screwdriver, and an 8mm socket.

I started by removing the rear lights from the car (remove the rear trim, disconnect the harness, undo the 3 nuts holding the unit in place) so that I could identify which pins led to which bulb. The innermost pin (so furthest left on the right hand light unit and vice-versa) feeds the positive terminal of the fog bulb while there is only one negative terminal that serves the whole unit.

From there, I replaced the units, but left the harness disconnected. With the flat head screwdriver, I released the plastic catch on the base of the harness plug and then used the screw driver to depress the small metal catch that holds the innermost pin in place. This enables the wire to be pulled free of the harness. Next up, I connected my 1.5m wire to the innermost pin on both sides of the car so the original wire and my new addition both feed the same pin, replaced the pin in the harness. Simply pop the plastic catch back down, reattach the harness and replace the plastic trim.

In order to protect the connecting wire, I removed the plastic trim at the back of the boot, and fed the wire into the void (there are a number of other wires in there (boot release, number plate lights etc) so it is a suitable place for the wire to rest.

Apologies for the low res phone image, but my proper camera is temporarily (I hope) disabled. As soon as it's back up and running, I'll get some decent step by step pics up, as well as of the new headlight bulbs and interior LEDs.