Replaced rectifier but tach still doesnt work

[xxturbowesxx]

I recently replaced my rectifier because i wasn't getting a charge to the battery. When i hook up the voltmeter to the battery and start the motor the voltage increases from about 12v to around 13(this was on the muffs around idle). the tach zeros when it gets power but doesn't react to the motor being started. What should I do next?

 

[Chris1956]

Re: Replaced rectifier but tach still doesnt work

Since the voltage increase when the engine speed increases, the battery is charging. Check the connection between the AC side of the rectifier to the tach's "S" pole. if that is good, you may have a bad tach. You should read some low AC voltage at the tach's "s" ploe.

 

[Barnacle_Bill]

Re: Replaced rectifier but tach still doesnt work

Also make sure you connected the gray wire to one of the yellow wires (at the rectifier) coming from the stator

 

[sschefer]

Re: Replaced rectifier but tach still doesnt work

What motor is it (year and model) I have 1990-2000 manual in front of me and can check the wiring for you.

 

[hkeiner]

Re: Replaced rectifier but tach still doesnt work

I recently had the same symptoms you had. No charging at the battery and the tach did not work. In my case, I replaced both regulators and the charging started to work but the the tach still did not work. I determined that the gauge was also bad using the below linked troubleshooting guide and replaced the gauge. Now the tach gauge works too. Your results may vary...

The troubleshooting guide may help you too. In short, it it best to use a multimeter to determine if the problem is due to a bad sender (regulator), a bad gauge, or bad wiring/connections/ground before replacing a part unnecessarily based upon a guess.



http://www.downloadingfiles.co.uk/teleflexfiles/gauges/page342.pdf

 

[xxturbowesxx]

Re: Replaced rectifier but tach still doesnt work

Thanks guys! im saving this issue for next week. ill figure it out. its a 1988 Mariner 150hp Magnum II. I plan on buying a new tach and keeping the packaging nice and testing it with the new one and if it doesnt work then go from there. I may just do a volt test with the motor on on the gray wire. what voltage am I looking for?

 

[hkeiner]

Re: Replaced rectifier but tach still doesnt work

I may just do a volt test with the motor on on the gray wire. what voltage am I looking for?

The above linked guide contains the following specs. I believe that these would apply to your motor and that the gray wire would be the SEND to GRD wire.

Voltages with engine running should be:​

IGN to GND Terminal: 12 VDC minimum.

SEND to GND: 5 VAC minimum at idle.​

 

[sschefer]

Re: Replaced rectifier but tach still doesnt work

Hkeiner, that is the correct info.