tach issues

[vernon morgan]

On the way back from a goose hunt today my tach stopped working. Then it would only work at 2000 RPM and above. Soon as it hits 2000RPM it goes to zero. Any suggestions?

[Barry Nave]

Alt. drives Tach.
How's the charging system doing.
Alt. goes south,Tach goes with it.
If you change the Alt. hang on to that pully.
Most or some new Alt. will have a smaller pully and this will give fault tech reading's.
Show's more RPM.

[A M A]

if u have a small pully were will u hook a tach to