What is the function of voltage/rectfier on OB motor

[Snoopy-2]

Trying to determine if my voltage-rectifier need to be changed.
My tach reads when off goes about 900 rpm, then when I turn key on to start engine it bottoms out and then goes back to about 900 rpm.
When I give it gas it goes to the bottom of the scale again and stays there until I got back ti idle.I don't have a volt meter to check if the motor is charging.
Where in the circuit can I put a volt meter to check my charging rate when running.

 

[Barnacle_Bill]

If you are talking about mounting one on the dash hook it to the purple wire coming off the switch. If just using a handheld meter hook to the battery. It should read about 13.5 volts with the motor revved up a little (2000 RPM)

 

[Silvertip]

The charging system on an outboard produces AC power. It is the function of the rectifier to convert that AC power to DC. The voltage regulator controls the output of the charging system to prevent over charging the battery. You were told in one of your other threads how to determine if the battery is charging. The tach signal (sense line) originates at the rectifier/regulator. The tach counts the pulses produced by the charging system. A twelve pole alternator produces 6 pulses/engine revolution. The tach then converts the number of pulses to an RPM reading.

 

[Snoopy-2]

I have checked the Pulse line and the only thing I read is about 8.volts and it did not change with rpm.Also the tach is not advancing.
Turn key on it goes from normal set position of 1,000 rpm to zero. When engine starts it goes to 1,000 rpm but as soon as I increase the rpm over idle the tack needle dives to 0 and stays there. No tach and unable to check charging condition.

 

[F_R]

Your voltage test at the pulse wire is meaningless. Forget that "test". If you can check the voltage at the tach, why can't you check the voltage at the battery while running to see if it is charging? If it is, then you have a faulty tachometer or wiring to it. Don't forget the ground wire is part of it.