2003 Volvo penta 3.0 gl tachometer operation question

[ronrymanr]

Would like some advice as to find and fix my nonfunctioning tachometer? I have located a female plug starboard engine side coming out of a larger harness.2 purple one black. Tried to match it up in my owners manual but C.N.F. forum pics will not allow me to post? It says file too large? First post .would anyone know if tachometer is a sensor type or alternator pulse type?

 

[spannerman]

Tacho signal is a grey wire from the negative terminal of the ignition coil.

 

[ronrymanr]

[QUOTE="spannerman, post: 7294852, member: 2577"] Tacho signal is a grey wire from the negative terminal of the ignition coil. [/QUOTE] Does the tachometer receive power from purple wire? 12 volts with engine running or just key turned on?

 

[spannerman]

The tacho shoukd have a red/blue wire which is live when the ignition is on, engine running or not.