VWDiesel.net The IDI, TDI, and mTDI source.

General Information => Upgrades (non engine related ) => Topic started by: ventureforth on September 29, 2010, 08:11:42 pm

Title: Would a MB diesel tach work?
Post by: ventureforth on September 29, 2010, 08:11:42 pm

Would a MB diesel tach like this one: http://cgi.ebay.com/ebaymotors/Mercedes-W123-Diesel-tachometer-tach-300D-300CD-300TD-/270640302272?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f036b48c0

...work off the W terminal on my 1.6NA alternator?

--EDIT--
Never mind.  I was able to find a thread about it.  This topic can be deleted.

Title: Re: Would a MB diesel tach work?
Post by: theman53 on September 29, 2010, 10:28:14 pm

What did you find out? I would love to know if it would work or not.

Title: Re: Would a MB diesel tach work?
Post by: rs899 on September 30, 2010, 07:21:47 am

Venture didn't provide the details of why it won't work, but anyway MB drives the tach from a crank sensor with some electronics.  It can be made to work with a lot of effort, but not simply off the alternator.

Title: Re: Would a MB diesel tach work?
Post by: bajacalal on September 30, 2010, 08:45:27 am

I found a tach that DOES work off the alternator, it was a from a boat with a BMW diesel marine engine with a similar alternator-based system. It has a full range of adjustment for fine tuning so I can set a baseline for the engine speed and once I do that, it should be pretty accurate.

I will post pictures when I get something working.

Title: Re: Would a MB diesel tach work?
Post by: dennis on September 30, 2010, 11:11:48 am

Volvo 760 D24T cars have tachs that work from the W terminal.

Title: Re: Would a MB diesel tach work?
Post by: ventureforth on September 30, 2010, 12:32:52 pm

Here's a good thread that discusses the MB and what would have to be done to make it work:
http://www.vwdiesel.net/forum/index.php?topic=20437.0

Would the volvo diesel tachs be plug and play, or need calibration?

Anyone ever use a tinytach?  http://www.tinytach.com/tinytach/diesel.php