A change of volts

Many years ago when volts were expensive, it was thought that only six of them was enough for the electrical needs of a motorcar, especially a small one such as a Volkswagen. A few years later, when the first Microbus was designed, nobody had changed their thinking, the Microbus had a six volt system. In the dim dark years of post-war Germany, this was probably reasonable.

It was twenty years later that I could actually afford to buy a second-hand example first model VW Microbus, the one with the split windscreen and a tiny rear window, to use for surfing trips up and down the coast, and everyday transport.

The current Microbus models had twelve volt systems, with loud stereos and bright headlights. The sickly, pale yellow glow of the headlights on mine, although legal, was neither adequate, nor cool. The fashion then was to mount as many quartz-iodide driving lights up front as could fit, apparently with the intention of leaving tracks of molten road tar behind you at night.

So I decided to upgrade the old bus from six volts (6V) to twelve volts (12V). Shouldn't be too hard, change the ignition coil and generator, pop in some 12V light globes, and it would be a bright shiny new day, or night. There were two potential problems: the starter motor and the windscreen wiper motor, neither of which had 12V equivalents of the same form factor, but with all the confidence of a newly graduated engineer, I was sure I could find workarounds. So, going boldly where wiser people fear to tread, I installed the 12V battery under the rear seat, a 12V ignition coil and new condenser, and the 12V generator.

It was about here that the first signs of the new and invigorating boost in volts became evident. A smell of melting plastic and a pop reminded me that the door was open, and the 6V interior light, after enjoying life in the fast lane for only a few glorious minutes, expired from an overdose.

No problem, just slip in a 12V globe. Time to see how the rest of the system will hold up on the enriched diet, starting with the cheaper bits. Replace the turn indicator flasher relay with a 12V version, and the turn indicator light globes. Yep, works fine, but what is that weird clunk every time I flip the switch?

Behold, the ancient flip out turn signal arms at the sides have awoken, after fifteen dormant years! They were still connected. Of course, after flipping out, they never returned completely, as in the olden days. Back then, they were legal and considered to be the height of sophistication in that the driver did not have to open the window to signal a turn with his or her hand. Easily disconnected.

Next, try the headlights, with the 6V globes. Wow, never seen the old VW Microbus light up like that, almost as bright as a normal... uh-oh, time to put in the 12V globes, and replace all the dashboard lights.

The horn sounded like it was being strangled, but at least it sounded, so I left it.

Now comes a tough one, the windscreen wipers. There is no drop-in 12V replacement. Under the 6V régime, they were as sluggish as an old man getting out of bed on a cold morning. Here is an approximate textual representation of their action:

Waaap. Waaap. Waaap, w a a...a a p

The last one happens when the rain has stopped and the dry windscreen offers more friction. Under the 12V régime, it was something like:

Wapwapwapwapwa screep...

The last one was where the wiper blade, under the influence of the unaccustomed centrifugal force, flew off and vanished. Maybe it went into a low Earth orbit, maybe it landed in a neighbour's yard. There were no sharp cries of pain, and if it ever returns to Earth, I am confident it will burn on re-entry.

The solution here was rain indicator lights, two orange lights mounted on the front and connected in series with the wiper motor. Obviously, they lit up whenever the wipers were turned on, indicating that it was raining. Not one of automotive technology's finest achievements, but it dropped the voltage and made the wipers work reasonably well.

The last problem seemed to be the hardest, the starter motor. No easy, cheap replacement option but, it does not have to run for a long time, so why not leave it as it is? With 12V on the 6V motor, the old bus started with a satisfyingly loud clunk and whirr, commanding respect from its younger relations lined up at the beach.

The old bus continued to give faithful service, slowly, very slowly, chugging from beach to beach up and down the east coast of Australia.

Log in or registerto write something here or to contact authors.