Faria Tachometer question

Barry F

Cadet
Joined
Jun 14, 2009
Messages
11
Hi All, Thanks in advance for your support.
I have a 2004 Reinell 200LSE and the Faria Tachometer has stopped working.
The supply voltage to the tach with the ignition on is 12.8VDC it has a good ground. With the engine running the voltage
to the signal return on the tach is also 12.8VDC, what should I be measuring on the signal return HZ ? VAC ?
Pretty sure the tach is crapped out because it is stuck at 1200 RPM but just wanted to make sure what I should be reading for a signal return, don't want to put in a brand new replacement and have it fail also.
I have read that the Faria brand isn't very good quality can anyone recommend a replacement that has the same input ?
Photos Attached
Thanks.
 

Attachments

  • Red Deer County-20120725-00090.jpg
    Red Deer County-20120725-00090.jpg
    52.9 KB · Views: 1
  • Red Deer County-20120725-00089.jpg
    Red Deer County-20120725-00089.jpg
    67.9 KB · Views: 1

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: Faria Tachometer question

The tach sense signal is not a steady state signal. It is a pulse (sort of a modified sine wave) that comes from the charging system. A 12 pole alternator therefore produces 6 pulses per engine revolution. So you would be measuring an AC signal. The tach is apparently toast because it should drop to zero with 12 volts applied with no signal on the "S" terminal. Tap the unit or give a quick right-left twist. If the needle doesn't move it has gone to tach heaven.
 

Barry F

Cadet
Joined
Jun 14, 2009
Messages
11
Re: Faria Tachometer question

Yeah that is what I suspected Silvertip, just to confirm the signal wire has zero volts until I start the engine then goes to 12.8VDC.
At this point I should be reading some range of AC voltage depending on RPM ?
Thanks
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: Faria Tachometer question

Yeah that is what I suspected Silvertip, just to confirm the signal wire has zero volts until I start the engine then goes to 12.8VDC.
At this point I should be reading some range of AC voltage depending on RPM ?
Thanks

I need to clarify that the information I gave you is for an outboard. If your boat is an I/O you either have an electronic ignition or points style ignition so the wave form would be very different than the outboard. Points open and close and electronic ignition is also a pulse. A service manual for your engine would tell you what to expect on that line.
 
Top