Crossed Wires

Do your headlights look dim? Does that little light on your speedometer not work? Did you even know there's supposed to be a little light on your speedometer? Not surprising, but, over time, most electrical systems fail. Dust, water, age, corrosion and the adverse elements cars face every day take their toll on its wiring. More than likely, if your car has never been rewired, it's overdue for one. For safety sake (i.e. burning to the ground), comfort of being able to read the warning lights on the dash (i.e. so it doesn't burn to the ground) and the convenience of seeing the map at night when you're lost are reasons enough to revamp the wiring in and around your VW.

With the backside of a Beetle's dashboard easily accessible from under the hood, electrical service, if deemed difficult from an enthusiast's point of view, is at least convenient to reach. Regardless, the majority of the connections can be made easily without having to remove too much of the car's equipment.

For a complete wiring harness replacement, first things first, disconnect the battery so the new harness won't be inadvertently damaged by a crossed "hot" wire during the installation. To make it easier to reach certain connections (the brake master cylinder and the rear tail lights, license plate light, etc.) the engine and gas tank need to be removed as well.

Since we are installing a pre-assembled harness from Wiring Works (via The Real Source) for a 12-Volt 1967 Beetle (minus a radio), all of the correct wires are accounted for (though some of the colors have changed from stock over the years). However, during the installation, you'll need to snip and reattach the slide connectors on a few of the wires, so proper tools are essential. Among standard screwdrivers, pliers, electrical tape and a utility knife, you'll also need wire/insulation cutters, spray silicon, slide connector pliers and a voltmeter. You shouldn't have to cut any of these wires to adjust them for length and proper connection. They are all pre-measured and pre-assembled for you.

Most important thing to remember when you're working with wires and electricity is to be patient. If the wires don't fit, don't force them. If you feel you have to yank, twist or crimp, you're probably doing it wrong. You need to be organized and plan ahead. Get a copy of the schematic for your car (visit www.vintagebus.com) and study it. Since it is a graphical representation of what's hiding behind the dash, it is neither to scale nor accurate to the position of the components (See Page 58). If all else fails, ask a professional for help, like we did. Rafael Gutierrez, master auto electrician at West Coast Classic Restoration, has seven years of VW wiring under his belt, and he showed us a few tips to make the job remotely comprehendible. On Page 63, we've also included a mini guide to purchasing new electrical components if yours have had it.

Now Where Do I Go?

How the System Works
The six- or 12-volt wet storage battery (1967 and later have 12-volt systems) feeds current to a solenoid which engages the flywheel teeth and directs current to the starter motor. To recharge the battery after the system (including lighting and accessories) has drained its power, the engine-driven generator (or alternator) creates a charge that is fed back to the battery via the regulator, which adjusts the amount of returning current.

The stock Volkswagen electrical system follows a scheme common to European cars known as a "Bosch" system. The difference between European and American cars is centered around the use of relays. Until recently, American cars only used relays for a few accessories (headlights, horn, etc.), while the "Bosch" system requires them for most all wiring configurations.

There are two types of relays, electro-thermal and electromagnetic. An electro-thermal relay operates equipment based on a given interval of heat. When this heat reaches a certain level, the relay cuts off the current. After cooling down, the switch again closes. An example of this method is employed by the turn signals. The best feature of this type of relay is that a minor amount of current can switch major power on and off. An electromagnetic relay uses current to magnetize and move a mechanical plunger, much like on the starter solenoid and the carburetor's valve jet.

What Goes Where?
The surrounding diagrams are based on a 1967 Beetle and represent the various under-the-dash components that can be found in most aircooled Beetles. The wire connections are color coded to the appropriate colored wire and show the location of each wire based on the component. As well, the wire number in each diagram corresponds to the charts on Pages 57 and 59. For example, Wire Number Three in the "Ignition Switch" diagram is the red wire with the black stripe that comes from the starter and fits into the ignition in the upper left post as shown.

If you have any doubts about a component's durability, it is best to replace it with a new one