# Ford 6640 tach/hourmeter



## jr in va (Apr 15, 2015)

My tach has stopped operating and so has the diff lock both of which need the alternator running at peak performance to do their job so I know a rebuild is needed there.Today,however, the hour meter stopped working.It is the mechanical type.

After I check the drive cable what else should I look for,if anything ? I sthis like the older models that once they stop the only cure is a new one?


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## chevytaHOE5674 (Mar 14, 2015)

IIRC a 6640 shouldn't have a cable for the hour meter it is electrical and needs the alternator to work.

If you replace the alternator and the tachometer, PTO, and Diff lock statt working but the hour meter doesnt then it will need to be replaced. That requires replacing the entire instrument panel.


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