Installing Hella Micro DE Fog Lights on VW R32 Using OEM Switch

With pics from my installation as well as information/pics from VW Vortex’s bostoneric and docs_r32

After installing Euro-spec HID headlights on my MKIV R32, I lost the fog lights that were integrated into the US spec headlights. I purchased Hella Micro DE lights, after reading about other Vortex installations by bostoneric and docs_r32 I decided to finally go ahead and execute my delayed installation.

The Hella Micro DE fog lights come with a wiring harness, relay, and switch. The wiring harness will be modified so that the existing fog light trigger wire in the OEM 10 pin harness can be utilized. The plug for the supplied switch is removed (cut) from the harness but we need the yellow trigger wire, it will be cut so that there is plenty of wire to run from the relay to the headlight connector. The relay is wired as follows (bostoneric's wiring diagram):

Relay Pole #s :
30 - red : battery 12v +
87 - green : Hella lamps
86 - yellow : trigger wire connected to OEM headlight harness PIN 2 (Gray wire with yellow stripe)
85 - black : splits to battery ground & Hella lamps ground

After removing the blue wire, the small ground wire, and the black and blue wires that were bundled with the yellow wire we needed, we are left with the following- red 12v +, black ground, yellow trigger wire, and the two connectors (black/green wires) for the fog lights:

For mounting the lights I decided that the depth required left me with only one mounting solution: mounting the lights behind the air and auxiliary radiator air intake vents on either side. I started by removing the bumper and rebar foam and then drilled holes as close to the 90 degree bend at the back as possible, the rebar foam may need to be notched to clear the bolts and any washers/spacers used. I drilled holes right on the edge:

Here are some pics from docs_r32’s installation, his holes are drilled a little more forward of the 90 degree bend:

I used washers and some nuts as spacers to square up the mounting surface and make the mount solid. Here are some pics of the mounted fog lights. I had plenty of clearance inside the CCF air horn but had to use a heat gun to reshape the auxiliary radiator air horn:

After mounting, I returned to the wiring. I cut the red wire (12v +) to get the fuse closer to the battery, about 10 inches long. After connecting the battery power and ground wires, I found the trigger wire in the OEM 10 pin harness and used a tap to tie the yellow wire to this wire, the gray wire with yellow stripe located in the PIN 2 location:

I then ran the drivers side fog lamp wire down beside the headlight and then the passenger side fog lamp wire across the top of the radiator core support and down beside that headlight. I used zip tie mounts and zip ties to secure the wires in the channel at the top of the radiator core support. Before reinstalling the bumper I tested the lights and adjusted them:

After reinstalling the bumper, I found that the fog lamps were just touching the grilles when snapped back in place, not enough to justify cutting but I will have to watch the plastic and see if the heat from the fog lights causes the plastic to warp:

Finished result: