terminal block--is it an electronic part???

[enginepower]

1995 90hp 3cyl serial 0g174918. I removed the terminal block thinking it is a rectifier and performed a diode check on it. I am reading open circuit both directions of all terminals. The setup also has a small voltage regulator/rectifier and charging system working ok but tach sticks at certain rpm's and doesn't move until a big increase/decrease in rpm's occur or if I hit the trim switch. The back side of the terminal block has that epoxy sealant stuff used to encase electronic parts of this nature. Anybody familiar with this setup and know if the terminal block is an actual rectifier?

 

[Texasmark]

Your tach signal is a grey wire as I recall (look on the back of the tach...red or red/purple or purple for power, grey for signal and black ground ) and comes from the rectifier/regulator module. Also on that module are the 2 yellow input voltage wires from the stator and red dc output and black ground wires. That module is a plastic, epoxy filled cup with 2 screws attaching to the mounting plate. The input stud for the starting solenoid is usually the power terminal block as it is there anyway and saves an additional part. I had the 90 and they were pretty close on everything but the 4th cylinder and associated parts. Other areas of the engine that need to join wires just do it at the bayonet connectors.

Mark

 

[GA_Boater]

Do you see the part on this diagram you are calling the terminal block?

http://www.crowleymarine.com/mercury...rts/554_80.cfm

 

[enginepower]

#24 boater. Yes I see it is called a rectifier, merc online catalog calls it a rectifier but have seen others call it a terminal block. 2 yellow wires from stator connect there then 2 more yellow wires connected in same spot go to the small voltage regulator/rectifier as referred by merc catalog. The center grey wire goes to my tach and another grey wire that connects on top of that one goes to the rectifier/regulator. Since the back of it has potting like it's protecting electronics, I would think it's an actual rectifier and it's blown since it is open circuit both directions on diode test.

 

[GA_Boater]

If you have opens in all directions, the rectifier is shot. You have make 8 measurements on total.

 

[enginepower]

I only counted 6 but yes, open on all measurements in diode check mode, even tried ohms and got nothing. I guess that explains why my tach is acting weird and possibly why the previous tach when I got the boat didn't work at all. Thanks for the input.