White, Yellow and Grey Wires (including wires with tracers) are for the Lights.Black Wires (including wires with tracers) are Ignition Switch Power.Red Wires (including wires with tracers) are Battery Power.VW wiring typically follows a few guidelines: This isn’t an article on how to completely re-wire your car, it is an introduction to some of the basics of VW wiring and a guide explaining what all those wires in your VW are doing and what those numbers on the switches and relays mean. Lights being dim or not working, the wipers not working, batteries dying, or odd things like the radio turning off when the headlights are turned on are more often than not caused by problems with the all the modifications to the original wiring over time. After years of working on vintage VWs, I have found that many electrical problems can be attributed to the original, old, dry and brittle wiring being modified and added on to by who knows how many people in the past. Unfortunately, this means that often times there are wires cut, spliced and loose throughout the car. As long as the basic systems in the car- the charging system and the lights- work, most people are content. One of the most feared and often neglected portions of Vintage VWs is the electrical system.
