JD 5420 tachometer issue

[sndy]

I have a JD 5420 and the tachometer isn't working right. Sometimes it won't work at all and other times it will bounce up and down. Is this just a loose wire? a sensor? There is no cable.

 

[beenthere]

:welcome: to the forum.

It may be the speed sensor, part no. RE519144

But then it may be a loose wire going to that sensor.

jdparts will show you where that sensor is located, if you can't find it.