Electrics

I am fitting a lot of additional electrical accessories to this car as described in the other topics in this section and am having to add quite a bit of additional wiring and fuses to protect the circuits. The car originally has a 12-way fuse box tucked under the dashboard on the left hand side in both left and right hand drive versions. This was supplemented by a number of torpedo fuses around the car: three under the rear seat in the Variant for the Eberspächer heater and rear window demister, and one clipped to the engine for the reversing lights. For the Fastback, these were all in the engine compartment. I am adding a few more for my extras.

Incidentally, I’ve been asked more than once if I’m fitting a second battery to power the additional accessories. The answer is no, because the battery only supplies power to start the engine and when the engine is not running. The majority of electrical accessories are only used when the car is running and many of the heavy current users are ignition-switched in any case. The alarm system draws a small continuous current, but all other accessories, such as the central locking and the window auto-lifter, take power briefly only when locking or unlocking. It is the alternator that has to cope with everything when running and it is highly unlikely that everything will be used at the same time. The original is rated at 55 amps and this can cope well enough even at tick-over.

The original fuse box and fuse allocations

1 2 3 4 5 6 7 8 9 10 11 12
Side lights Headlights Headlights Side lights Always live X Ignition switched
Side lights left Side lights right Low beam left Low beam right High beam left High beam right Licence plate light Emergency light system
Interior light
Electric fuel pump†
Cigar lighter
Heating*
Fresh air fan
Wiper motor
Heated rear window*
Temperature regulating switch*
Turn signals
Dash warning lamps
Horn
Brake lights & dual circuit warning lamp‡
* switch current † LE model ‡ where fitted X – ignition switched but off when starting

Additional torpedo fuses:

Under rear seat: In engine compartment:
Heater main current (16A)
Heater overheating current (8A)
Heated rear window main current (8A)
Reversing lights (under clip) (8A)

The new fusing for the main box

1 2 3 4 5 6 7 8 9 10 11 12
Side lights Headlights Headlights Side lights Always live X Ignition switched
Side lights left Side lights right Low beam left Low beam right High beam left High beam right Licence plate lights
Rear fog lights
Emergency light system
Interior lights
Radio
Electric aerial
Alarm activation signal relays
Cigar lighter
Heating*
Central locking
Hood and tailgate releases
Sunroof auto-close relay
Fresh air fan
Wiper motor
Heated rear window*
Temperature regulating switch*
Turn signals
Dash warning lamps
Oil temp gauge
Sunroof*
Radio*
Sat-Nav
Horn
Brake lights & dual circuit warning lamp
* switch current     X – ignition switched but off when starting

Additional torpedo fuses:

Under rear seat: In engine compartment: By main fusebox under dashboard:
Heater main current (16A)
Heater overheating current (8A)
Heated rear window main current (8A)
Reversing lights (under clip) (8A) Always live:
Electric windows auto-lifter module (25A)
Sunroof (25A)
Ignition switched:
Electric windows (25A)

The Omega K9 alarm has three modern blade fuses pre-wired in the loom: 1 at 15A for input and 2 at 10A for output to the interior light and the side lights. I have decided to accept these for simplicity. I am using the alarm signal output to flash the indicators instead of the side lights as Omega intended. The fused 10A output would feed the car’s own indicators (7A total) but would be overloaded if a trailer was attached (10.5A), so I have added a couple of standard after-market relays to take the load and keep the circuits seperated.

Headlights

The headlights were originally wired with the outer pair as the dipped beam and side lights and the inner pair as the main beam, only one pair was on at a time. The US models had sealed beams and were different. The full current was switched by the light switch from the X contact on the ignition switch, thus the current for the headlights comes through two switches, they are on only when the ignition is switched on and go off when starting. Soon after I bought the Variant, I added another relay to eliminate the voltage drop through these switches. I also arranged for the dipped beams to stay on when selecting main beam – all the better to see my way!

I have renewed the original Hella headlight units which have been discontinued. My local Hella dealer investigated for me and they came up with revised part numbers of 1K3 114 155–001 for the high beam and 1M3 114 178–001 for the dipped beam with sidelight. There is one snag, they didn’t have the brass earth terminal fitted but they did have the cast-in stump. So I needed to recover the earth terminal from each of the old units to transfer to the new ones and then carefully peen over the head of the casting to secure it.

Spaghetti

Electric Spaghetti, otherwise known as car wiring, is an art form. When I stripped the car at the beginning of this project, I didn’t think it would take as long as it has and I thought I could rely on my memory to guide me in putting it all back together. Well, it’s taken far longer than I expected and I’m consequently a bit older and my memory is struggling to recall what I need to remember. When I started work on the wiring at the front of the car I couldn’t believe how confused it had all become. But I’ve long known that wire, like string or wool, has a natural property that makes it become enravelled, apparently without any external influence. Just take a look at the scene below ...

The dashboard is in to check the fit and I have made a start on sorting out the main runs but I have a long way to go. I started off with the standard original geographical wiring diagrams that we all grew up with and found it very hard going, especially as the ones I had in my books were black and white with kryptic codes for the colour key. I soon found these in full colour on the Type 4 website and printed these up at A3 size. Then I came across the circuit-flow type of diagrams and found these to be so much clearer – once I had learned how to interpret them. They are very different! Here is a sample below for part of a Beetle:

Wiring diagramKey

  1. Wire colour, corresponds with colour in the vehicle.
  2. Part designation, refers to the description in the legend, here J¹ = headlight dipper relay.
  3. Circuit continuance designation. The number in the box indicates where this wire continues, this example goes to circuit column number 49.
  4. Symbol. Here, headlight L¹.
  5. Circuit column numbers to cross-reference to the legend.
  6. Internal connections (thin lines). These are not actual wires but are, for example, earth connections within light bulbs or parallelling straps within the fuse box.

The legend gives a list and description of all parts and gives the circuit number on the diagram.

I found diagrams for the European and US-spec 412s on the wiring diagram page of The Vintage Bus website, they have diagrams for a huge variety of Volkswagens. I have updated the originals to include all my additions, which has made the work of rewiring so much easier. The legends were, of course, in German, so I’ve had to translate these into English.

 

To be continued . . .