Help identifying diesel tachometer req'd - want to fit it to my car! - Page 2 - PeachParts Mercedes-Benz Forum

Stretch · #16 10-30-2010, 08:27 AM

In the following link the wiring instructions are given:-

http://www.superturbodiesel.com/std/adding-a-tachometer-t-97.html

I quote:-

"Plug white pickup sensor into it's base socket.
The pigtail of the amp base will have 3 wires- Brown, green, black.
Brown is ground, attach it to any clean ground connection in the engine bay.
Black is power for the amp and tachometer. Connect it to a switched power source (there is one in the glow relay) with an inline 3amp fuse, run that wire from the amp base to the black/red stripe wire on the tach pigtail to power both the amp and tach.
Green is RPM signal output. Run that wire to the green/stripe wire of the tachometer pigtail."

I however seem to have different coloured wires coming off of the tach amp "base unit".

The brown green and black are there - so that's OK

However, I then have a red and a yellow-with-green stripe.

On the other end - at the tachometer in the instrument display I have a wire of green-with-black stripe and a wire of red-with-black stripe.

I've taken the tach amp "base unit" plug apart and I see the following colour to pin relationship:-

Pin #1 => yellow with green stripe
Pin #2 => brown
Pin #3 => NOT USED
Pin #4 => green
Pin #5 => black
Pin #6 => red

Questions:-

1) Is this correctly wired?
2) Which wires from the base unit should I join to the 2 pin plug that goes into the back of the tachometer? From the info in the link I assume green from base unit goes to green-with-black on the 2 pin plug - but I'd like to check.
3) What are the other wires for?

techguy512 · #17 10-30-2010, 05:50 PM

Quote:

Originally Posted by Army

What are the other wires for?

Here are the pin definitions for the amp socket. This is for the US models, which came with tach amp P/N 001 549 59 32. This is also valid for the TWO PIN tachometers, not the newer 3 pin models that worked via the EGR computer.

Pin 1 - empty, no connection
Pin 2 - ground
Pin 3 - output to tach
Pin 4 - empty
Pin 5 - empty
Pin 6 - +12V
Pins 7, 8 and 9 are from the sensor at the harmonic balancer.

bobodaclown · #18 10-30-2010, 06:00 PM

You might want to check out this site:
http://mbelectronicupgrades.com/Tachometer_Amp.html

Stretch · #19 10-31-2010, 11:25 AM

Quote:

Originally Posted by techguy512

Here are the pin definitions for the amp socket. This is for the US models, which came with tach amp P/N 001 549 59 32. This is also valid for the TWO PIN tachometers, not the newer 3 pin models that worked via the EGR computer.

Pin 1 - empty, no connection
Pin 2 - ground
Pin 3 - output to tach
Pin 4 - empty
Pin 5 - empty
Pin 6 - +12V
Pins 7, 8 and 9 are from the sensor at the harmonic balancer.

Err thanks - seems a bit different from what I've got. I'll do some more investigative work - may be the other wires I have don't do anything...

Stretch · #20 11-02-2010, 11:07 AM

Does anyone have a picture of the bracket that holds the tach amp in place on the inner side of the left hand wing?

I'm having trouble sourcing one over here - I guess I could make one if I knew what it looked like.

Thanks in advance.

funola · #21 11-02-2010, 02:05 PM

Here ya go! If I were you, I'd mount it lower where it's cooler. Heat rises and that's what eventually kills the tach amp IMO.

funola · #22 11-02-2010, 02:09 PM

PM me if you need a bracket from across the pond.

Stretch · #23 11-02-2010, 03:00 PM

Great stuff thanks a lot - PM will be sent!

Stretch · #24 11-03-2010, 05:20 AM

Quote:

Originally Posted by techguy512

Here are the pin definitions for the amp socket. This is for the US models, which came with tach amp P/N 001 549 59 32. This is also valid for the TWO PIN tachometers, not the newer 3 pin models that worked via the EGR computer.

Pin 1 - empty, no connection
Pin 2 - ground
Pin 3 - output to tach
Pin 4 - empty
Pin 5 - empty
Pin 6 - +12V
Pins 7, 8 and 9 are from the sensor at the harmonic balancer.

Techguy512 - you are correct - I got confused looking at the wires coming from the harness (sorry):-

You can clearly see from the photograph (attached) that pins 1, 4 and 5 don't exist!

techguy512 · #25 11-03-2010, 07:44 AM

Quote:

Originally Posted by Army

....I got confused looking at the wires coming from the harness.....You can clearly see from the photograph (attached) that pins 1, 4 and 5 don't exist!

It appears that the socket you have is from the post 1984 diagnostic plug, and not the one that was supplied with cars fitted with the tach amp/two pin tach combination.

This is OK, as long as you rewire the plug to get it it to match the configuration required by the tach amp. For example, you should move one of the unused wires into the pin 3 position, and then run the pin 3 wire directly to the input pin on the back of the 2-pin tach.

Stretch · #26 11-03-2010, 08:56 AM

Quote:

Originally Posted by techguy512

It appears that the socket you have is from the post 1984 diagnostic plug, and not the one that was supplied with cars fitted with the tach amp/two pin tach combination.

This is OK, as long as you rewire the plug to get it it to match the configuration required by the tach amp. For example, you should move one of the unused wires into the pin 3 position, and then run the pin 3 wire directly to the input pin on the back of the 2-pin tach.

Great stuff Bob - thanks a lot.

I've got bits from all over the place:- the tach amp and the tachometer came from California, the wiring from a guy in Enschede (probably imported from the East coast USA), the bracket next to the front pulley from someone in Rotterdam... it is no wonder I've ended up with a mishmash of bits and bobs!

mike-81-240d · #27 03-16-2011, 05:26 PM

Did you ever figure out if the sensor needed a magnet in the crank? I'm gathering all the parts together, but that has me stumped.

Stretch · #28 03-17-2011, 04:56 AM

Quote:

Originally Posted by mike-81-240d

Did you ever figure out if the sensor needed a magnet in the crank? I'm gathering all the parts together, but that has me stumped.

No there isn't a magnet in the crank - there is a little peg that protrudes from the crank balancer and this "makes" a pulse from the magnetic sensor (I think it is a magnetic sensor).

Stretch · #29 03-17-2011, 05:05 AM

Take a look at post 15

Help identifying diesel tachometer req'd - want to fit it to my car!

For all of the bits I've collected

Thanks to funola I also have the little bracket for inside the fender / front wing to mount the tach amp.

degier · #30 12-07-2012, 06:31 PM

Stretch,

How´s it goin?
I am a man from the future, near the end of the world..right before 21-12-2012...and researching the same stuff.

Got my tach, two pin 85 model. Now the rest.

Via daparto.de tons of gear can be found like this cable:

Help identifying diesel tachometer req'd - want to fit it to my car!-screen-shot-2012-12-08-12.20.25-am.png

With this pin probably:

Help identifying diesel tachometer req'd - want to fit it to my car!-screen-shot-2012-12-08-12.20.14-am.png

But do see just mentioned benzine and turbodiesel. No NA 300 D. For this particular impulsgeber. But the head looks like your grey cable there. Did yours have such a plug on the end? which fits where? the amp?

Anyways..digging further elsewhere. Posting to see what happend with your tach.and bump.

Groet, Jan.