There you are driving down the road in your Carrera and you notice a wall of red light in your rear view mirror. Obviously, the law enforcement official behind you is a connoisseur of fine automobiles and just wants to compliment you on your excellent choice of vehicles (It could happen!).
In actuality, he has pulled you over for your own safety. What he has noticed from the rear, is that your car appears to be a motorcycle. The lights, he tells you, are all out on the right side of the car. Being curious, you take a look for yourself, and discover he is right. You thank him and promise to rectify the situation as soon as you get home. Because you have been so cordial, he completely forgets about your modest miscalculation of the posted speed limit, and sends you on your way (yes, this could happen too!)
The first thing you do after pulling into the garage is to check the fuses. They all seem to be in good condition. Upon further inspection you discover that it can not be a single bad fuse, because the lights in question are controlled by two separate fuses. One fuse for the front lights, one for the rear, on each side. For your next step, put a test light to the fuses and discover that there is no power. You cringe as thoughts of new headlight switch prices dance through your head. But, never being one to jump to conclusions, you decide to remove the headlight switch and check for power there. There is power there. How did it got lost between the switch and the fuse block?
The power, you see, has not become lost, it has met a road block. This road block is a diode that has gone bad and refuses to pass current in any direction. (A diodes job is to allow current flow in one direction only) Replacement of this diode is relatively easy once it has been located. It can be found under the dash near the headlight switch. It is about 70mm long, black with a clear insulator on one side. The part# is 911.617.108.00 and costs $16.67. Just unplug the old one, and plug the new one in.
After replacement, recheck all fuses and lights so that nice police officer won’t have any reason to pull you over again.