Tacho meter failure

[Tilikum]

Hello all,
My tachometer died a natural death. Bought a new one and cannot get it working.
Replaced the resistor (named kit)  at the output of the alternator (bypassing the regulator) and connected the tachometer with it's brown cable to the other side of the resistor. (The resistor is not connected to the alternator.)
Before the resistor I have up to 15 volts and at the the other side less than one volt.
What am I doing wrong, do I need a different sensor or is the value of the resistor not right. The supplier does not have an intelligent answer.
Thanks,
John,
"Tilikum" (Alanya, Turkey)

[SailingSeaDragon]

John,

The tach on Sea Dragon is "wired" into the oil pressure switch so that it is not energized until the engine is started and the oil pressure reaches an acceptable level. You may check your oil pressure switch.

Below is a link to Westerbeke tach/hour meter trouble shooting Bulletin (limited value).

http://www.sailingseadragon.com/Manuals/Tachometer.pdf

This does not answer your question directly. But I offer this just in case.

Good luck,
Garner

[Tilikum]

Thanks Garner,
All works from the oil pressure switch correctly. As our Tilikum's engine is a 1978 model, we have the old meter and alternator.
Before the outside diode I have, depending on the revs, about 15 volts and after the diode nil. Besides the diode there must be a resistor somewhere to get the voltage down, or is this part of the "kit diode"?
The diode was connected on the alternator outlet as the red wire to the regulator and the brown wire to the tach meter on the body of the diode, is that correct?
Can I still find these service bulletins somewhere on the net?
Thanks and best regards,
John

[S/V Deo Volente]

Just a couple of thoughts, the tach uses an AC output so you should use the AC setting on the meter. Have you checked the ground on the tach? Does the tach needle go to zero or does it float?

[Randy]

Speaking of tachs. Mine is original to the boat (1979). Beginning sometime last year, when I start the engine, the tach does not register. Only when I rev up the engine will the tach "catch" and work normally. Is this a symptom of a loose wire, etc... or just an old tach on it's last leg?

[S/V Deo Volente]

Randy,
I would look at the wiring to the field terminal on the alternator. There needs to be current flow to "excite" the alternator. Your tach is probably fine.
Bob

[Henri Hali]

Randy:
I had the same issue with my original (1980) tach last year.
I checked te connections at the alternator and found one loose.
Problem solved.

Henri