I have TC25D tractor the tachometer and hrs meter stopped working

[Pipercub]

Hi tachometer stopped working and hr before would work then stop .i unplugged green wire at alternator and metered through it to dash wire not broke . I did check voltage when tractor running see if any change in voltage figure should get like 13 to 14 volts but was only getting 12.85 the gauge needle does move like vibrating .i was thinking alternator bad is why tach not working . Any help would be appreciated

 

[stevem5215]

Yep, probably. Take it off and take it to a alternator rebuilding shop.