tc40 tach irratic

[rubicon2]

Hey Guys. Tried the ag forum but no luck. I have a tc40d hrdrostat. All of a sudden the tach will not read until I reach about 2000 rpm. The needle is then a little wiggly but readable. Checked connection at gauge and alternator. Wires are tight. Any suggestions? Thanks.

 

[mjw357]

I'm guessing your tach works using some sort of pickup or sensor that sends pulses from a notched wheel or magnet attached to the flywheel? Have you looked to see if anything is loose or bent down on that end of things?

 

[rubicon2]

I think it gets tach reading from alternator.

 

[dave1949]

I think it gets tach reading from alternator.

I think that's correct.

My tach is squirrely for 5-10 seconds every time I hose down the engine and radiator. Rain doesn't seem to have the same effect though.