Rear fog light control unit - where?

[chrisbbarnes]

Okay so my 1998 300TDI didn’t come with a rear fog light, so I wanted to install one. I bought the light and switch and installed them both. Upon testing, it didn’t work. Did I get the led wires the wrong way round, no. Referred to my only wiring diagram, the good old fashioned Haynes manual, to ponder which wiring diagram should I be using.

The one I’ve been using most is the one labeled all models from 1991-1996. Not let me down until now. Different colour wires going to the switch, so now I’m looking at the diagram 2000 onwards (the next one in the book). When going through it and my trusty Electrical Library book I can’t seem to locate where the Rear Foglight Control Unit is. This is my only explanation why I can’t get the light to work.

So what wiring diagram should I be looking at? Does my car have a RFCU? And where should I be looking for it?

[p38arover]

This one - 1999?

160982

Or this one - 1997?

160983

160984

Why bother with an ECU? Wire it directly.

[chrisbbarnes]

Thanks for that. When I get round to sorting out my dash I will look at this RFCU if I find its faulty (if it’s there) I will just replace it with a relay. Problem should then be solved.