Home » This Vintage Aftermarket Bosch VW Accessories Catalog Features A Radio That Makes Your Car Slower And Fantastic Turn Signals And Taillights

This Vintage Aftermarket Bosch VW Accessories Catalog Features A Radio That Makes Your Car Slower And Fantastic Turn Signals And Taillights

Bosch Top

I have a few larger-scale stories percolating at the moment, but I can’t just sit here and pretend I’m not incredibly distracted by hyper-important documentation of The State Of Taillights And Turn Indication Past as presented to me by this 1952 Bosch Accessories catalog. There’s some fascinating things in here – well, fascinating to automotive lighting fetishists such as myself – and, yes, a radio that I’m pretty sure will make your car slower, at least a bit. Let’s take a look.


One thing worth remembering as we explore this catalog a bit is just how minimal the electrical systems of cars were in the early 1950s. You may expect this on a simple, frugal peoples’ car like the Volkswagen, but even American cars of the era, with many more power-assisted creature comforts, were likely to use things like vacuum power for wipers and power door locks and windows and so on, because electric motors were still expensive and complex. So, an accessory electrical part catalog like this one from 1952 is going to have what we’d consider today to be really basic stuff.

Stuff like this:


Yes, a reverse lamp! These wouldn’t be required in America for another 15 years after this catalog was published, and later in Europe, but for forward thinkers who liked to see when going backwards, Bosch had you covered. These look to be almost identical to the factory-installed reverse lamps that VW was using on US-spec cars in 1967.

As you can see in the corner of that picture there, early VW taillights were tiny, simple things, and only performed two functions: taillights and brake lights. The indication of turns was handled mechanically via wonderful mechanical semaphores or trafficators:

While you or I may find these absolutely charming, there were many people in the semaphore era that felt the visibility of the little arms wasn’t great, and the arms, being electromechanical things with moving parts, were much more likely to break than a simple light. Many cars already employed blinking light turn indicators, and Bosch gave VW owners this option as well, at least three years before VW implemented them for 1955 US-spec cars.

These aftermarket turn signals could be the earliest blinking-light turn signals you could get for your Beetle, at least ones specifically marketed to VWs. Here’s what Bosch’s indicators looked like, front and rear:


They’re kind of an odd design, really, and I’m kind of surprised that they seem to be different units, front and rear, when you’d think the same unit would have worked for both. It’s grayscale printing in the catalog, but for the era I’d expect that the front ones were clear and the rear red, as this was an era before amber indicators on either end.

I think the front ones look a bit better than the rear ones, which visually compete with the taillights in a sort of strange way. Still, I like them, and I suspect they would have been more visible than the semaphores.

One odd thing, too:


The blinker in the big cutaway picture is of a different design than the one shown in the catalog! What are you trying to pull here, 70-year-old Bosch catalog?


Also interesting is the blinker switch, which clamps onto the steering wheel with the familiar lever we’ve all used (this is where you can make your BMW driver jokes, by the way). But what I like is that the semaphore indicator switch is still there, right at the top center of the dash, meaning a Beetle so equipped would have redundant methods of turn indication, triple, even, if you count hand signals. That’s impressive.

Also notable is that clock in the driver’s side glove box door, which I would have thought might appear in this accessory catalog, but doesn’t. I didn’t think those were factory?

Okay, I’ve teased you long enough with this radio-that-slows-you-down business. So what am I getting at? Here’s the radio in question:


Nothing too crazy there, right? Just an early-’50s Blaupunkt AM radio. So why would that affect the car’s performance? Well, here’s why:


You see, to run this radio, your little 1131cc air-cooled motor making all of 25 horsepower would need this second generator installed, making the 150 watts needed for the radio. That means a new double pulley on the crankshaft which now must spin the stock generator and the extra radio generator, and I know that had to take some sort of toll on engine output, and when you’re only dealing with 25 hp to start, I’m gonna guess you could even feel it.

I feel it when my Nissan Pao has the A/C on, and that pulley is adding drag to the engine. I don’t think a generator is as taxing as an A/C compressor, but the Pao has over twice the power, so I’m standing by my claim that when the radio is cranked, you’re going to be driving slower, at least a bit.

What I don’t know is if that alternator was directly wired to the radio, or if it fed the car’s electrical system as a whole, which would make it pretty cool as a backup system, and maybe could charge the battery faster?

Fascinating stuff, right? That’s why I’m here, friends!

Share on facebook
Share on whatsapp
Share on twitter
Share on linkedin
Share on reddit

39 Responses

  1. The third photo is absolutely NOT a reverse lamp.

    It’s a nebelscheinwerfer, that is, a fog lamp. Just like the ones shown in the second photo on the front are labeled nebelscheinwerfer.

    On the front, these would be clear or yellow. On the rear, these are typically tinted red, just like the taillights, but much brighter, in order to shine through fog.

    I don’t know why you guessed that it’s a reverse light; it’s not as if it wasn’t labeled and Google translate wasn’t there for you the whole time.

    German cars often have a single fog lamp on the back of the car as well as the pair on the front, because it’s foggy in Germany a LOT, and German law often holds a driver partially or even fully responsible for being struck from behind. Rear fog lights are also very common in other areas of Europe, but I don’t know if traffic law supports their presence in quite the same way German law does.

      1. Mostly tube heater filaments, plus high voltage plate current (generated with the use of an electromechanical vibrator, which switched the +6 VDC at some low frequency, which was then stepped up by transformer and rectified for suitable plate voltage). The tube grids require very low current, analogous to the gate current of a MOSFET.

        1. I’m not an Electrical Engineer, but I work with enough to say that passes the sniff test. I’ve got to look up these vibrating inverters now!

  2. 150 watts is about 1/5 of a horsepower assuming perfect efficiency, but taking friction and electrical losses into account plus the fact that small generators are inefficient and this one is tiny, well it’s a wonder that this moves at all.

  3. It’s interesting that the accessory turn signal lever is on the right side. BMW and Peugeot both did that until the mid-late 70s when they were forced to standardize. BMW even had right side turn signals on motorcycles until 1980. Oddly VW AFAIK always had the factory turn signal lever on the left.

  4. I wonder if there’s any double generator Beetles still surviving in that configuration today? Don’t think I’ve ever seen so much as a picture of that setup before

    1. Because they didn’t exist in the 50s. I had a 69 Beetle that still had the stock generator, and I added a large amp for the 15″ subwoofers I had instead of rear seats. When I big bass note hit when I had the headlights on, the whole car would turn off for a second or two! I replaced it with an alternator, and while it still had issues with not enough electrical power, it wouldn’t turn off anymore!

      1. I think they went from 6 volt to 12 volts for the 1967 model US. If memory serves they also went from generators to alts. that same year. But I also have felt your pain. I think my family owned close to 20 bugs and bus models from the 50s to the present.

        1. My folks bought a new beige 1967 — best year ever: full tubular bumpers, low-profile hubcaps, vertical-face sealed beams, reasonably-sized taillights (plus the added back-up lamps), a few more H.P. and 12V electrical. Everything started going to hell after ’67.

          1. I don’t know about that. I liked my 69, although I’ll mention that it wasn’t entirely stock even when I bought it. Details I liked – more engine vents in the cover. Most importantly – IRS (Independent Rear Suspension.) I drove my step-father’s older convertible, and spun it out in the rain leaving a stoplight, something I never experienced in mine.

    2. I dunno about the assertion below that there weren’t bigger generators, but I’d say it’s quite possible that the radio runs on 12V and the generator connects directly to it.

  5. Those Bosch accessory turn signals resemble (but again are different from) some of the ones on early Ponton Mercedes which were mounted on the sides of the front fenders right about at cowl level. That far back, too, approximating the visibility of semaphores.

    Even on my 130hp Honda Fit I feel the drag from the a/c compressor, mainly since the rev hang goes from “not much at all, really, I don’t see what the big deal is” to “none at all it’s headed for idle RIGHT NOW”. Since I drive with a/c off 90% of the time (it’d be 95% plus if there was an override switch to have the defroster without a/c) things are a lot more jerky with it on because my clutch timing is based on how it responds with a/c off.

    1. I feel like a/c compressor impact on engine performance correlates more with displacement than power. Inertia, etc. I guess. My WRX is tuned even (primarily to address rev hang and other icky drivability characteristics) and a/c kicking on (also uncommon for me) is like whoa. I guess a 2.0l is just a 2.0l when there’s no boost. Finally, same as you again, shift timing is all different and harder to do smoothly when a/c is running. Even with factory rev-hang mostly gone from the tune. Once you get into 3-ish liter V6’s and bigger, the rotating parts seem to have enough mass not to be bothered.

    2. I’m surprised that there isn’t a button combination on your HVAC control panel to override that. My civic just need me to press 3 buttons at once and the A/C became something I could override when the DEF mode is on.

  6. I had a 57 oval 30 years ago when I was a student. It had 6V electrics and a 170W generator, driven by a 1192cc 30PS power house. Lights on AND music (a modern Alpine cassette radio, hidden under the dash) was a no-go, there was not much electricity left for charging the battery… So in winter I had to take the battery out in the evening and carry it all the way up to the 4th level, where my apartment was (to keep the battery warm and at least a little charged for starting in the morning)
    I did not install a second generator, I switched to a 1300cc big block with 44PS and 12V. What a relief! And so much power – 50% more than original!

  7. Trafficator? Another new word I’m delighted to learn! “I identify as a Trafficator. If that offends you then you’re the one with a problem!” Do you think “CHiPs” would have had more respect of it was called “Trafficators?”

  8. WAIT A MINUTE. That diagram is telling me that the word “blinker” is actually the German language word for turn signal/indicator? It’s not native Massachusettsan?

  9. Ref the clock in the driver side glove box: It was probably a wind-up mechanical clock and thus of no interest to Bosch and their electrical business.

  10. So if we could upload here I could submit the cool photo of my Grandpa and his brand new 1961 VW flat bed transporter. (hint) He was so proud of that pos. But in the UP of Michigan he had to remove the battery and bring it inside to keep it from freezing in the winter time. Being a proper Swede, he found this annoying as it ate into his drinking time. After a couple years of that crap he bought a proper mid 60s GMC pick up. Swedes don’t tolerate inefficiency well.

    1. A 1952 catalog? Transistors had just been invented, and were strange and expensive (the first commercial transistor radio appeared in late 1954). This was certainly a tube(valve) radio.

  11. Is it possible that the radio required 12 volts? Therefore a separate 12v generator was needed, given Volkswagens of that age had 6v electrical systems.

    1. No reason for the radio to require 12V. It’s not any harder to build a 6V radio, might be easier, as most tubes(valves) had 6V filaments anyhow, just a different vibrator and step-up transformer to get the plate voltage.

  12. At a previous job (grinding performance camshafts) one of the owners bought and restored a Fiat Topolino. One of its oddities was a switch for the headlights that allowed you to switch them to a lower power output to save engine power for climbing hills! When my boss found this out, he decided to do something about the fact that Fiat clearly thought the power output was barely enough – his solution was to design a ‘hot’ camshaft profile for it to increase the power output. We ground a master pattern and used it to regrind the stock cam. Years later the business has been sold and moved to the other side of town, and somewhere on the shelves with all the other master patterns will be one for a Topolino, that will probably never be used again!

  13. I remember the AC in my old very temporarily owned 89 or 90 Honda Civic made a definite difference, to the point where flipping the AC off getting on the onramp was “throwing on the turbo”.

  14. The radio doubles as a 140W heater. The marvels of thermionic valves.
    Two or three minutes of humming before you hear anything.

    When I was small my mum drove a 1947 Austin “12” that had traficators ( probably Lucas). SOP when approaching a corner was to flick the switch that was in the middle of the steering wheel, then twist around and smack the inside of the b-pillar to get the thing to pop up.

  15. I love the semaphores. Much cooler than simple blinkers. However, they need to be longer so you could use them to slap an annoying pedestrian.

    1. There’s a bit of a problem..if you forget to flip the switch and retract them a person exiting the car can smack into them and break the arm.
      Wiring them to an ignition switch controlled circuit is the fix but that wasn’t stock at least on the Morris.

    2. Let’s flip-flop for the new era: semaphore add-ons for modern cars! They’d be a natural on my PT, but I’m also visualizing a shiny C8 Corvette swinging out an angry, angular directional blade to warn the masses which direction it’s heading next.
      (Maybe as part of a whole new “catalog” of aftermarket auto enhancements — “printed” on “paper” and available by “mail”!)

Leave a Reply