Rectifier output ????

[Moody Blue]

Got the motor running first time this year, 92 Mariner 40HP 4cyl. Added a tach earlier this spring and after firing up the motor the tach was dead. Checked for signal at the tach - none. Checked for signal at the rectifier terminal that tach wire is hooked up to - none. Checked other rectifier terminal - signal. Switched tach wire to the other terminal and tach works fine. I thought each side of the rectifier would be the same ??? Output voltage is 13.8V @ idle and higher as RPM is increased so I am assuming the rectifier is OK. I am puzzled. Should a voltage not be present at either terminal ?

 

[Laddies]

Re: Rectifier output ????

Ring test the alt. for continuty if you have continuty between the 2 yellow wires a none to ground you have a bad rectifier, chances are thats the problem--Bob

 

[Moody Blue]

Re: Rectifier output ????

I will test as suggested as soon as it stops raining. If the output voltage is good, doesn't that mean the rectifier is good ?

 

[phatmanmike]

Re: Rectifier output ????

if you have 12 volts across your battery when the motor is off, and 12 volts also when it is on(running) the rectifier is bad. if you have 13 - 17 volts running, then its good