Rabbit Diesel Tachometer

[Molcajete]

Was there ever a factory Diesel Rabbit that was produced with a Tachometer?
I had a 80 Diesel Rabbit sedan in the mid-80's, but I don't remember if it had a tach. I now have a 80 Rabbit Caddy Pickup and would like to install a tach, depending on the cost and availability.

[bscutt]

You can buy a Tiny Tach (about $100 on line) or visit VWCADDY's site, he has a kit (see links page on this forum). I don't know if the Turbo Rabbits had a factory tach or not, pretty sure the NA ones did not.

I have the Tiny Tach and I love it, it works great and took about 15 minutes to install.

[Molcajete]

Great! Thanks for the info, Bob. I'll check it out.

[Fatmobile]

There is a rare gasser tach;
setin the dual-hole, early instrument cluster
and vwcaddy's should work with that.

I have the later instrument panel and can use a GTI tach,
with one of vwcaddy's setups,
a dakota digital tach converter, run off the alternator's W terminal,

I swap cap and resistors over on the GTI tach, to make it work off the W terminal.

[doonboggle]

Regarding ....

There is a rare gasser tach; .......... a dakota digital tach converter, run off the alternator's W terminal,

.... on my workbench, I have a gasser tach now installed in my 81 p/u diesel cluster.
I used the original cluster's mylar circuit board.

According to Dakota for the DSL, the 'input' goes (I presume) to the tachometer.
But with no terminal, what do I connect to?

ANYONE??????

[Fatmobile]

There is a place for the tach plug in the instrumnet cluster plug.
You'll have to follow it back to the tach to see which one.

and you'll need a plug wire/terminal from another cluster, to splice into.

Otherwise, I think there are nuts on the tach terminals.

[doonboggle]

Thanks fat ... but not sure you are following me.

I want to add a tachometer to the diesel pickup I have; in place of the big clock that came from the factory in the instrument cluster..

On the web are several postings, etc. about doing this by using a Dakota DSL signal conversion unit. However none of them ... and I have studied all closely ... describe where-how to connect the feed wire coming from the DSL 'outlet' terminal ... to the tach that is installed to the cluster in place of the clock.

There is a mylar circuit board sheet that is on all 81-84 rabbit instrument clusters. The clock is connected to one of the embedded circuits. However, the tach has no terminal, plug, etc. to connect the inlet wiring to.

Others have successfully done this ... but unfortunately none of them cover this final step in the process.
doon

There is a place for the tach plug in the instrumnet cluster plug.
You'll have to follow it back to the tach to see which one.

and you'll need a plug wire/terminal from another cluster, to splice into.

Otherwise, I think there are nuts on the tach terminals.

[Fatmobile]

I think I understand and answered you question perfectly.
It's like you didn't read my answer.

So let's find out where we got lost.
Did you understand this statement?:

There is a place for the tach plug in the instrumnet cluster plug.

Even though you went from clock to tach, you still are using the same "mylar circuit board",..
gauges went from top to bottom (or is it the other way around) but the copper traces are the same.

this one?:

Otherwise, I think there are nuts on the tach terminals.
You'll have to follow it back to the tach to see which one.

maybe changing the order helpped.

From the nuts on the tach posts,
follow the copper traces back to the plug where all the other wires plug into the instrument cluster.
there won't be a connector in that spot,..
put one there and splice it to the dakota digital

[doonboggle]

Thanks again Fat.

There is a place for the tach plug in the instrumnet cluster plug.

Am posting images of the left over cluster (first image) the tach had been removed from before I got it. I put the clock from my cluster in it and marked the whole thing as 'spare', with a note attached.
The other one (second image) is my diesel cluster with the clock removed and tach installed.
Don't see a 'plug' ... but .........

I think there are nuts on the tach terminals.

.... I think this may be the answer. On the images I've marked some differences; namely on the first one a shiny trace end that apparently had a post thru it previously, with a nut.
Then on the second one, the post can be seen, with the nut I put on it when I reassembled everything. Also note the t2 other shiny ends that have no posts protruding ... whereas on the first one they are there.

So I think it is fair to say that I 'stupidly' overlooked those differences. That's what I get for staying up so late every night trying to figure this out.

If I understand the rest of your comment, I can now trace the circuit line from the post protruding from the tach back to the cluster large plug ... locate the wire it connects to ... and splice into that wire at some point with the 'input' from the DSL.
Am I reading that correctly?

Thanks again !! I feel like I'm getting somewhere now!

[Fatmobile]

If I understand the rest of your comment, I can now trace the circuit line from the post protruding from the tach back to the cluster large plug ... locate the wire it connects to ... and splice into that wire at some point with the 'input' from the DSL.

There probably won't be a wire to splice into,.. there was never anything connected to that tach terminal when it was a clock.

The 3 arrows messed me up, I thought you were saying they were all for the tach,.. but 2 of them are for the temp gauge (in clock mode).

After realising that, it's obvious the left-most tach post has a copper trace going right to the plug, easy to follow,.. top #5

you'll need a plug wire/terminal from another cluster, to splice into.

The wire will actually have to be from another instrument cluster wiring harness,.. from another car.
Unless you can find a wire/terminal that isn't being used and swap places.

[doonboggle]

Thanks Fat ... but am now confused again. But first let me try and clarify the images posted.

The second one ... with the 3 arrows. The far left and the middle arrow point to the circuit board holes where the clock's mounting 'posts' protrude ... just like the 2 at the bottom . Neither of these 2 holes had any evidence of having nuts screwed down onto them previously ... due to the fact that the tach. has no mounting posts (or otherwise) to protrude here.
The 3rd arrow on this image points to another circuit board hole that does in fact reflect it had a nut previously screwed down onto it ... when the tach was in this gas cluster.
This becomes more evident in the 1st image ... where it's arrow points to that particular previously unused terminal post hole ... now with a nut on top ... recall please that that circuit board (1st image) is the diesel version. Also, the 2 connection legs sticking up above the tach will be trimmed off ... just like the circuit board shows in the 1st image from the gasser.

Hope that clarifies a bit.

Now for my confusion; and I'll colorize my points to distinguish them from your verbiage .....

If I understand the rest of your comment, I can now trace the circuit line from the post protruding from the tach back to the cluster large plug ... locate the wire it connects to ... and splice into that wire at some point with the 'input' from the DSL.

There probably won't be a wire to splice into,.. there was never anything connected to that tach terminal when it was a clock.

Right ... see above. But now with it being used with the tach, tracking it back to the cluster plug will show what harness wire it goes to ... does it not.
The 3 arrows messed me up, I thought you were saying they were all for the tach,.. but 2 of them are for the temp gauge (in clock mode).
After realising that, it's obvious the left-most tach post has a copper trace going right to the plug, easy to follow,.. top #5
Totally lost. There is no post to the 'left-most' hole in the circuit board.
No idea what this is addressing???

you'll need a plug wire/terminal from another cluster, to splice into.

The wire will actually have to be from another instrument cluster wiring harness,.. from another car.
Unless you can find a wire/terminal that isn't being used and swap places.

Also all of this last part is confusing.

[Fatmobile]

The second one ... with the 3 arrows. The far left and the middle arrow point to the circuit board holes where the clock's mounting 'posts' protrude

No they are not.

Those 2 arrows point to the temp gauge mounting holes for

2 of them are for the temp gauge (in clock mode).

Guests,.. gotta go will continue later.
... continueing later :... clock mounting holes don't have a trace going to the voltage regulator

[Fatmobile]

Right ... see above. But now with it being used with the tach, tracking it back to the cluster plug will show what harness wire it goes to ... does it not.

Seems like a question,.. but it's placed right before the answer,.. is it not?

Totally lost. There is no post to the 'left-most' hole in the circuit board.

Aha, but is there a:

left-most tach post

?

Tach as 3 posts, one is the most leftish.
Which one?
The left-most one.

If all the last part is confusing then look at the wiring harness plug going to the cluster,..
when you realise there is no wire/terminal going to the top spot, 5th over,..
you'll realise there never would be a wire plugged into there on a diesel,
because there was no tach,
and since the clock and tach share the same mylar circuit board
that spot is reserved for a tach signal wire ,... just what you are looking for.

[doonboggle]

SUCCESS ... hopefully...
At another web site came across an image that depicts where to connect DSL input signal ... under far most upper left nut ... which is to the left of my far left arrow of the 3 that I inserted. in my posted image.
At the same time he mentioned to use the bottom-right leg that was attached to the clock as a connection point in case one plans on having a center console clock ... which I am.

All those nuts, protruding posts, screws, etc. got the best of this old phart.
Sorry for being so dense. Now I can begin mounting my DSL and running the necessary wiring.
Thanks again.

Right ... see above. But now with it being used with the tach, tracking it back to the cluster plug will show what harness wire it goes to ... does it not.

Seems like a question,.. but it's placed right before the answer,.. is it not?

Totally lost. There is no post to the 'left-most' hole in the circuit board.

Aha, but is there a:

left-most tach post

?

Tach as 3 posts, one is the most leftish.
Which one?
The left-most one.

If all the last part is confusing then look at the wiring harness plug going to the cluster,..
when you realise there is no wire/terminal going to the top spot, 5th over,..
you'll realise there never would be a wire plugged into there on a diesel,
because there was no tach,
and since the clock and tach share the same mylar circuit board
that spot is reserved for a tach signal wire ,... just what you are looking for.

[avocado]

You can buy a Tiny Tach (about $100 on line) or visit VWCADDY's site, he has a kit (see links page on this forum). I don't know if the Turbo Rabbits had a factory tach or not, pretty sure the NA ones did not.

I have the Tiny Tach and I love it, it works great and took about 15 minutes to install.

Wow, that Tiny Tach looks really neat. I think I'll be getting one of those in the future.

Too bad it's digital though. I know its cheaper, easier, and likely more accurate, but I hate the look of the digital displays in my bus - its the only thing keeping me away from more Dakota Digital Gauges. Oh well.

Thanks for the tip!