Factory Dash Options

by Richard Atwell
(c) Copyright 2004-2011


Is that tachometer you purchased on eBay genuine? What years were the cut-offs for the changes in instrument facia? Are you obsessed with this baywindow thing and if so what on earth is a Fahrtenschreiber and does it have anything to do with the Burrito Breakfast you ate at EveryBus this year? All these questions will be answered and more in this installment of "Baywindow Clocks, Trip Odometers, Tachographs & More".


Ever wondered what goes in the 3rd spot in your instrument cluster? There's a blank plate that reserves a spot for the clock. The clock was an option available from 68-79 and only shipped from the factory as part of the 1978 Champagne Edition II (CED II) models (aka "cow-poop" edition) unless you put in a special order for it at your dealer. Both busses I've pulled clocks from were CED II models. You could also purchase the clock afterwards from some VW dealers.

The clocks matched the look of the rest of the gauges and fell into three categories:

clock blank styles
  • 68-72 dark gray face with a lt. gray disc in the center (and no second hand)
  • 73-75 with grayish face and no disc
  • 76-79 with black face

I've found working clocks in the junkyard for $10-20. You can end up paying $100+ for ones on eBay or Samba if your local junkyards are devoid of bus parts. Here are some other examples of the facia changes using the speedometer as examples:

early speedo mid speedo late speedo

As you can see, the addition of the clock really completes the look of the dash. The last photo is from my own bus and it's a quartz model. The earliest 68-72 model is a mechanical clock and they are often found in broken condition. Keep this in mind when you are bidding on eBay and the seller won't confirm whether or not it works.

Visit this VDO clock repair webpage to help diagnose problems with the mechanical version.

Trip Odometer:

early trip odo mid trip odo late trip odo

The trip odometers are indeed cool but finding one is the real challenge because they were very rare options. To make matters more difficult for US folks trying to locate one, KPH units are far more abundant than MPH units and they were not well advertized by the US dealers. The miles unit is actually a combo unit.

trip odo part number

If that wasn't difficult enough for the serious parts hunter there are three styles of facia for baywindow buses as previously mentioned. If you find the perfect trip odometer for your bus you've found a real treasure worth paying for. Many of these units are brought over from Germany and sold at high prices by folks looking to support their vintage beetle restoration hobbies (look up how much a set of NOS semaphores or an original Hazet tourister tool kit goes for these days!!!).


Contrary to popular belief the baywindow dash did not have an optional tachometer. Once in a while on eBay or Samba, "bus" tachometers come up for sale either as singles or as part of a complete instrument cluster. The last one I saw was offered for $300 and included a KM speedo with trip odometer to give you an idea of the sillyness of the pricing.

Here's an example of a recent phony:

fake tachometer

These faux tachometers are either VDO units from other VW/Audi models and mounted to fit the bus instrument cluster or are modified to look original. A red needle when the rest of the gauges have white needles is dead give-a-way that you are dealing with a forgery so don't get fooled. Instead, purchase a modern VDO tach and appropriate mounting ring for the clock location instead of wasting your money on an old piece of junk being proferred as NOS. Order the 220-09101 mounting ring from Bus Boys.

mounting ring

Some insist there was a tachometer available and other say no, so why the debate? The German army used a combo tach/temp gauge made by ONG that looks stock (for 1972 anyway):

ONG tachometer

M535 Tachograph:

Another source of the confusion regarding the availability of the tachometer is a single m-code in the fiches: M535 Tachograph. The tachograph was a device used to record trips made during a 24 hour period. Laws requiring people to record the trips they made, such as laws governing commerical truck drivers, made the tachograph a necessary option. The baywindow bus was heavily used as a commercial vehicle (mainly in Europe) and so this dash option was available there.

The tachograph records how long and how fast the operator was driving on a piece of paper. Because baywindow buses saw little commerical use in the US compared to Europe it explains why these units aren't seen in the US (a tariff placed on imported commerical vehicles in 1971 by the US Govt which killed sales).

So how did it work?

A piece of paper was inserted into the back and locked with a key by the business owner to prevent tampering by the driver. The clock inside rotated the paper while a needle scratched it. The paper was backed in red with a white covering which left a red mark as the needle erased the white. As the speed increased the device made a mark further towards the edge of the paper and in this way the company knew when and how fast the driver went during the day.

See this video for another look: Top Gear 1978 footage (about 1 min into video).

paper disc

There are three known manufactures of this part for VW (VDO, Motometer and Kienzle). The Motometer unit was called the Diehl Co-Pilot according to 1973 literature and was probably the brand the factory used.

VDO fiche 6/79:



Diehl Co-Pilot


instrument cluster front instrument cluster rear tachograph unlocked


Along with VDO, Kienzle was a clock OEM for VW.

Why does this one look so weird? It's because it went in the same loction as the radio after the dash was modified by opening up the slot. What you see at the bottom of the first picture is an ashtray. The bezel around the whole unit is there because the European dash was painted metal not the padded texture of the US spec vehicles so this design matched the instrument cluster.

Kienzle front Kienzle side Kienzle unlocked

These photos below are for a non-bus tachograph that my father-in-law has in his Peterbilt truck. Mannesmann merged with Kienzle and both later merged with VDO which is now part of Siemens. Big fish always eats the little fish.

Peterbilt front Peterbilt part number Peterbilt discs

Part numbers:

The USA microfiche from 1/79 that I have shows option M535 as the tachograph. If you look at Illustration 104 you'll see item 1A but because of the resolution of the scan it's always been hard to make out exactly what it was because unfortunately there was no 1A listed in the US fiche to describe it. The speedometer was item 3 and I would have expected a 3A but then I realized that a special panel was required to house the tachograph.

FYI: Tachometerwelle is German for speedometer NOT tachometer.

From German fiche:

Other numbers I've seen:

M557 Gas Heater Clock:

So what was the heater time preselector option mentioned above? Well, there was a variation of the clock that contained a timer to run to operate the gas heater. Assuming the battery didn't go flat you could wake up to a toasty bus or a a burned down one (just kidding!). This particular clock sold for $250 on Samba (where I grabbed the photo from).

grey timer black timer

From German fiche:

Here's a photo of a 411 clock that's interesting because so many indicators have been combined into one unit. It's too bad modern vehicles that try for the one gauge design like the BMW Mini can't get it to look as nice as this old model.

411 timer

M557 Wiring:

timer terminals

OK, you've been lucky enough to find the gas heater timer clock on eBay but you have no idea how to hook it up. Send $5 in SASE to:

Gas Heater Timer Instructions
c/o Ich liebe Deutsch Fahrzeuge
9801 Metric Blvd.
Austin TX 78758

OK, enough with the joking. There are 4 contacts on the back of the gas heater timer clock + the "hole" for the instrument light:

Bosch terminal designations aside, this hookup is really quite simple: the clock timer acts as a bypass switch for the gas heater timer switch. When the clock timer is set the ignition key position (off) prevents the heater knob from activating the gas heater when you set the temperature. When the timer activates it powers the same terminal that the heater switch would if the ignition key was on.

BA6 Instructions:

My DC came with the original BA6 manual. Although it was translated into 6 languages, for some reason the last page is only available in German. Google helped provide this crude translation.

BA6 pg1

BA6 pg2 BA6 pg5

BA6 pg6 BA6 pg15

Fahrzeuge mit Schaltuhr für das Heizgerät

Vehicles with a timer for the heater

Mit der Schaltuhr kann die Einschaltzeit des Heizgerätes innerhalb 24 Studen beliebig vorgewählt werden.

The timer can turn the heater on within a 24 hour period.

Die Schaltautomatik ist in die Schaltuhr eingebaut.

The automatic switching is built into the timer.

Die Einstell skala trägt die Ziffern 1 bis 24 entsprechend 1 Uhr bis 24 Uhr.

On the inner scale, the numbers correspond to the 24-hr. clock.

Die kleinste Teilung beträgt 15 Minuten.

The smallest division is 15 minutes.



Wenn einmal die Zeituhr um mehr als 12 Stunden verstellt wurde oder die Batterie nicht angeschlossen war, ist beim Vorwählen der Einschaltzeit auch auf die Stellung der Tag/Nacht-Anzeige (e) zu achten:

When the timer is set for more than 12 hours in advance or the battery has been disconnected, consider the following when selecting the position of the day / night indicator (e) in the right window:

weiß: Tageseinteilung von 6-18 Uhr
schwarz: Nachteinteilung von 18-6 Uhr

white: day schedule of 6am-6pm
black: night schedule of 6pm-6am

Während des überganges von Tag auf Nacht und umgekert (6 und 18 Uhr) erscheinen beide Farben im Fenster.

During the transition from day to night and vice-versa (6am-6pm) both colors will appear in the right indicator window.

Die jeweilige Farbspitze zeigt an, ob es Tag oder Nacht wird.

The respective color indicates whether it is day or night.

Wenn die Farbe der Tag/Nacht-Anzeige nicht der Tageszeit entsprichte, würde das Heizgerät 12 Studen später als gewünscht eingeschaltet werden.

If the color of the day / night display does not correspond to the time of day, the heater will activate 12 hours later than desired.

Die Zeituhr wird durch Hineindrücken und Drehen des Stellknopfes eingestellt.

Push the knob and turn to set the current time so the day / night indicator is correct.

Einschaltzeit vorwählen


Zündung aus. Stellknopf (a) in der Mitte der Uhr linksherum drehen, bis der Einstell zeiger (b) auf die gewünschte Einschaltzeit auf der 24-Stunden-Skala (c) zeigt. Wenn im Sichfenster (d) ein rotes Farbsignal erscheint, ist die Schaltuhr einschalt bereit.

Ignition off. Turn knob (a) in the middle of the clock and rotate left until the pointer (b) indicates the desired time on the 24-hour scale (c). If a red color appears in the left indicator window (d), the timer switch is ready.

Jetzt den Hebel (A) bis zum Anschlag nach unten ziehen. Temperatur regelknopf (B) rechtsherum drehen und die gewünschte Heizleistung einstellen. Zur vorgewählten Zeit schaltet die Uhr das Heizgerät automatisch ein und nach etwa 15 Minuten wieder ab, wenn bis dahin nicht entweder der Motor angelassen oder das Heizgerät durch Drehen des Stellknopfes nach rechts ausgeschaltet wird. In diesem Falle erscheit im Fenster (d) ein grünes Farbsignal.

Now pull the heater lever (red lever on right) to the bottom position. Turn the temperature control knob (B) right to the desired heat output setting. When the timer activates, the clock turns on the heater automatically and runs about 15 minutes, unless interrupted by the engine starting or the heater timer control knob is turned off. In this case, a green color will appear in the left indicator window (d).

Während das Heizgerät arbeitet, leuchtet die Kontrollampe im Temperatur regelknopf.

While the heater is working, the control lamp lights up in the temperature control knob as usual.



04/08/04 - Created
05/20/05 - Added Kienzle photos
07/06/06 - Added Karl's clock comparison photo
03/07/07 - Added image from my VDO fiche collection
11/30/08 - Added Trip Odo (miles) photos (Courtesy of Michael Weary)
05/06/09 - Added instructions for M557 clock
05/11/09 - Added M557 photos (Thank you Mike Smith)
09/06/11 - Fixed broken photos, added translate button, updated footer
07/15/19 - Google update: new adsense code, removed defunt translate button