tackometer quit working

[massey 471]

On my 471 Ferguson the tack quit working the hours meter still works.Need a wireing diagram. I didn't see a cable so I am not sure exactly how it is suposed to work. Any Ideas?

 

[rjmack]

iirc, electrical tachometer runs off coil.

 

[massey 471]

Since it is a diesel not sure about a coil I will try to trace wire to the alternater, Thanks

 

[rjmack]

Since it is a diesel

lol!... yup, i guess that pours water on the coil idea.

are you saying you can't tell whether the tach is mechanical or electric?

 

[massey 471]

I know it dosn't have a cable so I am thinking I need a wireing diagram to trace all of the wires comming out of the tack If you know how to get a wireing diagram it would be appreciated the local dealer is not much help, thanks

 

[rjmack]

you might try an engine manual.

if it's a perkins you shouldn't have any trouble finding something.

look for the tachometer sending unit/pickup... probably in the area of a rotating mass... maybe flywheel or crankshaft? could be camshaft too... unless the injection system is electronic it has to pick up the signal from some mechanical source. think of the rotor in a distributor cap... every time it goes by a certain point it sends a signal.

so if you determine the engine and then find out how they deal with the tach issue, you should find the sender.