M920 - manual tachometer needed

[farmer73]

Is there a manual tachometer that operates based on the spinning of the internal portion of its cable and requires NO 12v or 24v power source?

1980 M920 Cummins NTC400 - speedo/tacho not working; truck starts and runs for 20 seconds then quits. Would be interested to the know the RPMs at all times without electrical issues blocking it.

Thanks!

 

[kubotaman]

If you are just trying to see what the RPM is for testing purposes, you can use a regular M-series Tach like on your M818 or M35A2. The tach drive and cable should match up

 

[MrMikey4026]

There is a thumbscrew on the pump run solenoid that defeats the electric solenoid. Just screw it in and it should run forever if an electrical problem is occuring.

 

[farmer73]

If you are just trying to see what the RPM is for testing purposes, you can use a regular M-series Tach like on your M818 or M35A2. The tach drive and cable should match up

Thank you!

 

[farmer73]

There is a thumbscrew on the pump run solenoid that defeats the electric solenoid. Just screw it in and it should run forever if an electrical problem is occuring.

Thank you!