mercury 850 tach

[mmeeks]

i am wiring a tach to my 850 and i found the tach connector on the control box. it has 3 prongs in it,2 are inline with each other and 1 to the side. i figured out what was what and now the problem i have is that the wire to tell me what the rpm's are is not hooked up in the motor. its a brown wire and if someone can tell me where it goes i think the tach will work, pictures would be better but anything is better that nothin. serial number is 4153848 if that matters.

 

[Moody Blue]

Re: mercury 850 tach

The tach connector on your control contains +12V, GND and tach signal. You need a harness to connect from the control to the tach on the dash.

The brown wire in the engine harness is the tach signal wire and can be connected to either of the yellow stator wires on the rectifier. If original, it is probably still connected to the switchbox but that connection is no longer used with the newer tachs.

What type tach do you have?

 

[mike1245]

Re: mercury 850 tach

maxrules.com will have what you need

 

[mmeeks]

Re: mercury 850 tach

just an aftermarket tach from advance, im really just using it to fine tune the carbs and get the idle down where i need it.

 

[Chris1956]

Re: mercury 850 tach

Hopefully that tach is compatable with the outboard stator, which is what powers it.