Well Jon goaded me in to writing this piece, so here’s information based on my experience of wiring my tube framed VW. I have been asked in the past to do wiring jobs, but prefer to show how people to do their own work. This provides a great opportunity for one to become very intimate with their cars, so when problems arise you can quickly diagnose the issue and apply the proper repair.

I am no means an expert, so consider this a living document as others ideas and experiences can be incorporated.

Basically you will need some tools, some knowledge of electricity and materials.

With a few exceptions, the frame of car is used for the negative side of the circuit, so this simplifies most of the wiring as you are only dealing with the positive side for wiring.

However when I first wired my buggy, the second time I took it out I had some intermittent electrical issues. I thought even with hard motor mounts I had a good ground connection from the engine back to the rest of the frame. A wide ground strap was installed and all my problems disappeared.

You will also need a plan.

As with any project, without a plan, you will be floundering around and ultimately frustrated. Also you may end up with a weekend of sitting by the fire as your camp mates are off and duning.

The Plan Part One:

1st thing I looked at was "what does the motor need" to make it run and continue to run.

Well, with a standard VW engine it requires:

1. 12 volts to the coil.

2. Charge line "B+" on the generator to battery.

3. 12 volts through a lamp to D+ input on the generator.

4. A momentary 12 volts to the starter solenoid.

5. 12 volts to the starter.

6. Lastly a good ground from the engine back to the negative side of the battery.

So out comes a blank piece of paper and I draw these connection points.

Next is the gauges/senders, idiot lights and what not.

Then lastly the lights themselves.

At this point I have not started to connect the dots, per say. Just kinda laying everything out, grouping them into areas where they appear on the car.

Now I need a way to control these points and a distribution system to get power to them from the positive side of the battery.

Now comes the creative part.

Now I wanted a minimum number of switches, so I decided on two. One three position with a momentary at the 3rd stop (off, run and start) and a second with off, on, on to control my lights, first on was whip and the 3rd position for all lights, so the drawing they goes.

Next comes the distribution, or fuse panel or bus bar.

Some people prefer fuses some prefer circuit breakers, personally for me I like fuses as when they do go they give you some indication on why they let go. (More on this later)

With my car I found a pretty nice two bus fuse panel, each side has it’s own positive feed. So I will b controlling the engine electrics from one side and my lighting from the other. The engine side of the fuse box will be controlled by the RUN position on the switch, so instead of running a sack full of wires to the console, I add a relay to turn on this buss, the lighting buss will be on a constant energized (CO) state for the lights.

So now I add the fuse panel and relay, and draw a line from the positive side of the of the battery to the contact side of the relay then the other side to the bus I want to control (switched). I then pick on of the positions on the CO side, draw a line to the positive input (or common) side of the switch, then a line from the RUN terminal to the coil side of the relay. The other side of the relay will be connected to ground. Lastly a line connects the battery positive to the CO bus. I now have a fused distribution ready to connect the remaining circuits.

A brief word about relays.

A relay can be used so the switch will not see the total load (amps/current) of the circuit. This advantageous to those flame throwing driving lights you want to use. Some driving lights can draw up to 12 amps, and even though there are switches rated at 30 amps I prefer to use relays to switch the lights and fuse accordantly.

With that said I connect the coil side of my two relays to the lights connector on the switch and connect a fuse point to the common connection of the switch. Each of the contact side of the relays gets it’s own fuse and a single relay controls one light. My tail light are also controlled by the head light coil side of the relay. I use Lazar Star Micro B LEDs, and they have a very small draw. Lastly the whip connector of the switch goes to the whip connection, powered by a fuse point.

So I now have lights, the next item is the gauges and idiot lights.

I run separate circuits for each gauge and idiot light, if one circuit goes down I have the other, this also includes separate senders for oil pressure, those dual senders don’t seem to last very long and it just gives me a little piece of mind.

Fuse point (switched) to gauge to sender, fuse point to lamp then to sender. For simplicity I light the gauges with these feeds.

Lastly the engine requires a 12 volt at the coil, fuel pump, oil cooler fan, to the starter solenoid (through the start position), 12 volts through the ALT lamp to the D+ side of the generator and finally the battery to the starter.

Your picture is probably looking pretty busy at this point, use colored pencils and transfer to a new sheet for you final design. It will be assumed that all ground points will be wired to the frame or grounded to the a housing that gets back to the negative side of the battery.

The Plan Part Two:

Ok you have your connections but where do you place all this stuff?

First look at your car, how you organize all this is how far you want to go.

The three main things is:

1. Access to the fuse box.

2. Access to the controls.

3. View of gauges and lamps.

1. I welded in a new plate that can be easily be gotten to, (incase I need to look) also gave me a good path for the harness as I fab it all up.

2. Doesn’t make sense if you can’t get to the switches when your belted in. I have a Super Shifter which is offset. Careful cycling of the mechanism showed I can mount the two switches with out problems with interference or shorting.

3. My gauges and lamps are with in my peripheral vision, and unobstructed as I’m looking out the front of the car. You may prefer a more "in your face" arrangement.

Ok, draw some boxes on where items will be grouped (ie console switch box, ect). Now you have your plan, next is getting some tools and materials together.

Materials and Tools:

Ok, so your gonna need a few things:

Tools:

Crimpers.

Dikes or electrician scissors.

Nut drivers or wrenches.

Wire strippers.

Soldering iron (electric or butane).

Multimeter.

Materials:

Wire.

Shrink wrap.

Spiral wrap.

Connectors, multi or Cal Term.

A sack full of tie wraps.

Electrical tape.

So with the tools, your crimpers should be easy to manipulate with one hand, big cushy grips, and jaws that align. I use Valcom, which have been in faithful service for over 20 years. I also use electrician scissors for my stripping and tie wrap cutting. Go get a nice pair, then take them to your local knife/scissor sharpening service. They will align the blades and put a nice hone on the edge. If your unsure of stripping wire with scissors, try some practice pieces until you can "feel" of the conductor with out nicking. The scissors should be able to be manipulated with one hand. No sense in having fore arms like Popeye.

Dikes can leave a nasty edge to tie wraps, with scissors you cut across the wrap and 99% of the time you get a blunt that won’t bite you.

With tie wraps you need to be considerate of a few things. If your tying coax cable (radio) do not pull too tight as the center conductor has a foam core to keep it a particular distance from the outer shield. What this will do is deform the core and change the impedance.

Tie wraps are expendable, I use them to keep things organized as I’m lacing out the loom. I tend to go through a sack full, and the garbage can fills up quickly. Our 99 cent store is a good source for the expendables, but after that I reach for the good (ie mo’ money) stuff.

Tie wraps should face the same way, this is a personal thing with me. If your taking the time, why not make it look good. Also rotating the wraps so all you see is the strap and not the tie point is a nice thing.

 

If you want to impress and really put in the time, learn wax cord lacing

     

I’ve looked around the Spruce Goose and amazed on the workmanship as well as the hours of craftsmanship.

Ok, the solder iron. I use it mostly for shrink wrap. A little butane one has a great port for applying heat to the SW. Other wise I’ve used my Bic, just watch burning.

Cal Term type or compression terminals:

These are used extensively in my project. The colors indicate the gauges of wire they will accommodate. Typically your "Reds" with have no value, Blue and Yellow are the ones you want.

Buy in bulk, as I’ve been frustrated on more that one occasion with going to the store to get some more. I would not recommend removing conductors to accommodate the connector.

The multimeter is your friend:

Commonly know as a VOM (voltage, ohm meter) this will help you determine a host of problems from the MH to setting up your buggy. They are cheap and no tool kit should be without one.

Wire:

I’ve seen some buggies wired with CAT 5, as well as solid core wire. Heat distribution is aided by conductor size an amount of conductors. Once the magic smoke gets out, there’s no putting it back.

Even more info on electrical here