VW Rev Counter Retrofit

[keytouch]

Since upgrading my engine from the 1.6d CS to the 1.9d 1Y, I have decided like many others to fit a rev counter.
I don't have a clock, just the fuel gauge and temperature gauge. So I decide I would like to fit an original VW rev counter to leave an uncluttered dash.
Courtesy of NWVW I now have the diesel rev counter which will be part if my dash pod upgrade.
I intend to change the deteriorating ribbon PCB for the veroboard version in the wiki. As well as fitting the rev counter and every ally upgrading the gauges to the plasma lit versions from campervan culture.

The rev counter looks in good condition, one of the fitting lugs is broken but that should be resolved with a washer.
Here is the new counter.


Now for wiring it up I understand I need a 10V positive, earth and the sense signal from the W terminal on my alternator.
The rev counter has a 3 pin connector on the back, can anyone tell me which pin is which?

And also, does anyone know what this type of connector might be called it where I could buy a plug that fits?

[lloydy]

I thought you need the rev counter pcb?

[keytouch]

From my understanding the rev counter PCB just provides the 10V pos, earth and W sense connection. All of which I can creatively produce with fly leads.
Though I stand to be corrected, and if it is a bit more fiddly then I will find the way to overcome with help from here I'm sure.

[lloydy]

Will be great if you get it working, will save people buying a pcb

[keytouch]

I'll also add that I only have 1 oil pressure sensor and no buzzer of doom so the circuit is much simpler as it is not using the rpm figure to switch between 2 oil pressure sensors.

[ctange]

The rev counter has a 3 pin connector on the back, can anyone tell me which pin is which?

Your pin 1 goes to minus

Your pin 2 goes to a pin on the 10 Volt regulator TCA 700Y, along a long convoluted road, and on the input-side, so the revcounter do NOT get 10 V regulated.

Your pin 3 goes down to the conector pin 4+9

This is read from a instrument from a JX engine.

And also, does anyone know what this type of connector might be called it where I could buy a plug that fits?

There is no real conector other than this:

[keytouch]

Thank you very much.
So even easier than I thought, it just runs off 12V.

[ctange]

So even easier than I thought, it just runs off 12V.

Yes, suprisingly it do no use the 10V regulated.
The pinout for the TCA700Y is in the reverse order of standard 7810 regulators.
I will check the connections again

[keytouch]

Not much progress on this at the moment. Have been slowly gathering all the components for hardwiring the electrics. Just waiting for my ebay resistors to turn up from China.

The veroboard layout in the wiki is for petrol but it seems to be correct for early diesels too without buzzer of doom. It even has a "spare" LED that is in exactly the correct position for the glow plug LED.

[keytouch]

So today I connected the VW rev counter up to positive and negative from the lighter socket. And ran a wire around the van from the alternator to the rev counter.

It works! Sits around 900 at idle and foot on floor peak is at about 5000 revs.

So at least I know that when I hard wire the dash pod I can wire in the rev counter too once I have run a wire from the alternator up to the dash pod sir the "W sense" connection.

This may well be one of the easiest mods going.

[t25driver]

did you ever get this mod fitted and working and did you just flywire the fuel and temprature gauges to.

[CovKid]

When hardwiring, you hang on to (or procure) the original membrane rev counter connector (just snip that section off) and just solder flyleads to the back of it. Thats how I did it recently anyway. Obviously when you have a stock dash and no existing rev counter this connector won't exist so you either have to wing it or get one from a scrap membrane. I much prefer the hard-wired dash as apart from being reliable (at last) you have a lot more room to modify or add new facilities. If you use hot glue, you don't even need the veroboard even if preferable.

I recently fitted a green LED clock (centre) that also displays outside temperature and starter battery voltage, plus two green LEDs (and matching resistors) to replace the old dash bulbs. I disconnected the dash dimmer as it was no longer needed/valid whereas with regular bulbs it was essential.

Next project is to swap the green ones for RGB tri-LEDs so I can switch between red, green or blue colours for a bit of fun. Theres a lot you can do to improve a stock dash very cheaply but hardwiring is the starting point.

Original rev counter much tidier than one screwed on the dash. Its also possible to convert a diesel counter to petrol and the other way around but you do need neat soldering skills plus the alternative components.

The old electric time clock is a bit dated now and very inefficient. Even the original LCD clock is somewhat superceded by better modern units with more facilities at a fraction of the price.

[Buckaroo]

mine has all 4 pins in the rear of the clock.
I'm going to assume I'll need to wire up pins 1,3 & 4.

[steveo9007]

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[Stesaw]

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