Author Topic: tacho censor details  (Read 1788 times)

aquapore

  • Able Seaman
  • ****
  • Posts: 107
  • Karma: +0/-0
  • Boat Model: bavaria 41
  • Boat Year: 2003
tacho censor details
« on: September 22 2021, 12:39 »
I have a d2-55 engine with a dud tacho which is beyond repair.

Does anyone know the electrical character  of the tacho sensor.

Regards

Aquapore

sy_Anniina

  • Old Salt
  • *****
  • Posts: 263
  • Karma: +6/-0
  • Boat Model: Bavaria 40
  • Boat Year: 2001
Re: tacho censor details
« Reply #1 on: September 22 2021, 17:06 »
First I would check the wiring and all the fuses on the wiring diagram.

How do I know? MD22 engine with dead tacho.. bought already a Henric alternator-connected-tacho, but found one loos connection and one tripped fuse.

BR,

Tommi
S/Y Anniina

SYJetzt

  • Old Salt
  • *****
  • Posts: 320
  • Karma: +11/-0
  • Boat Model: Cruiser 46
  • Boat Year: 2005
Re: tacho censor details
« Reply #2 on: September 27 2021, 11:49 »
D2-55 Engine has a magnetic sensor on the flywheel, connected to the MDI, which converts the signal to serial and then to the tacho. See attached document.

aquapore

  • Able Seaman
  • ****
  • Posts: 107
  • Karma: +0/-0
  • Boat Model: bavaria 41
  • Boat Year: 2003
Re: tacho censor details
« Reply #3 on: September 30 2021, 12:39 »
Thanks for your reply.
My engine is a D2-55 presumably "A" version 2002 build. I don't think it has an MDI.
I will look at the tacho input signal with a oscilloscope and try to find a replacement.
My original shows burn marks caused by water ingress.

Does any one have a circuit diagram of these units. I will try to repair it.

Regards

Aquapore.

SYJetzt

  • Old Salt
  • *****
  • Posts: 320
  • Karma: +11/-0
  • Boat Model: Cruiser 46
  • Boat Year: 2005
Re: tacho censor details
« Reply #4 on: September 30 2021, 14:33 »
I think you're right about the missing MDI.
Maybe check this link https://www.manualslib.com/manual/1025286/Volvo-Penta-D2-55.html?page=94#manual
Seems it is a magnetic (hall?) sensor with direct connection to the instrument.