Rectifier for 1987 Merc 90HP

[ppeter4685]

A boat dealer parts guy checked out my tach that was not working properly and said the problem was most likely the rectifier, not the tach, so I bought a rectifier. It is at least somewhat embarrassing to say I can not find the rectifier on my motor. Can anyone give me some help? I have removed the cover over all of the electrical parts on the side of the motor opposite from the side where all of the throttle linkages are, looked behind the oil tank also on the same side of the engine, and see nothing that resembles the new rectifier.

 

[JWH0420]

Re: Rectifier for 1987 Merc 90HP

its on the shroud plate above the coil in center of plate ... not sure if ur replacing the right part or not but thats where it is

 

[ppeter4685]

Re: Rectifier for 1987 Merc 90HP

Thanks for the help. Given that the tach needle swings back and forth, sometimes quite wildly, while the engine is running at a constant RPM, do you have an idea about what might be wrong if it isn't the rectifier? Thanks again.

 

[oldman570]

Re: Rectifier for 1987 Merc 90HP

If replacing the recitifer dosen't fix the tach problem, check ALL wire conections at the battery, starter sel. for bad conections. Testing the sender wire between the tach and rectifier would be the first test I would do then test between the selinoid and recitifer. Also check the battery ground at the motor.
Best of boating,
Oldman570:facepalm: