VW Electrical System Basics

One of the most feared and often neglected portions of Vintage VWs is the electrical system. As long as the basic systems in the car- the charging system and the lights- work, most people are content. Unfortunately, this means that often times there are wires cut, spliced and loose throughout the car. 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. 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.

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. VW wiring typically follows a few guidelines:

• Red Wires (including wires with tracers) are Battery Power

• Black Wires (including wires with tracers) are Ignition Switch Power

• White, Yellow and Grey Wires (including wires with tracers) are for the Lights

• Blue Wires (including wires with tracers) are for Indicators (turn, oil, high beam, and flasher)

• Brown Wires (including wires with tracers) are for Grounds

Knowing that, if you take a look at the VW wires attached to an 8 terminal (used in 1961 through 1966 models) fuse box, you’ll typically see red wires on one side, a pair of fuses with white wires, a pair of fuses with yellow wires, a pair of fuses with grey, white-black, white-red wires, and a fuse with black wires. The terminal at one side is battery power, the terminal at the other is ignition power, and the 6 terminals in between are all for the headlights and running lights. Later models add more key and ignition power fuses, 1 more at each side for the 10 terminal box and 2 more at each side for the 12 terminal fuse box.

One major thing to note is that the power to the front of the car, the main red power cable, pictured above on the left side of the fuse box, is not fused. It runs from the battery or voltage regulator, all the way to the headlight switch, and from the headlight switch to the ignition switch and fuse block. Additionally, the ignition power to the coil, from the ignition switch, is not fused. That means that two of the most important wires to your VW running do not have a fuse. We highly recommend running a manually re-settable circuit breaker or a heavy duty main fuse on the main power wire as a safety measure. 

We’ve put together a list of most every electrical terminal and color wire used by VW in all models up to 1974. We don’t get into the fuel injection wiring which is used as early as 1968 in Type 3s, but even the rest of the wiring in the 1968 and later Type 3s still follows the below information. VW added more colors as the years progressed but the same basic information usually applies.

VW added additional colors with newer model years, but this should give you a good map of sorts for the spaghetti under your hood or dash. Using this list, some patience, and a few electrical tools such as a test light and some wire striper-crimpers, wire, and electrical connectors you should be able to patch and repair any issues in your aircooled VW. If your wiring is beyond repair, or you just want to start with all new wiring, we offer complete wiring harnesses for most VW Beetles, Karmann Ghias though 1974 and Bus models up to 1967at Jbugs.com. We also offer main looms for most air cooled models to ensure that the main power harness from the engine to the front of your VW is in good shape.

-Sam Mebane