Can anyone tell me why the Tachometer wont work on a DC1317 Chipper?

[InnovativeTreeLLC]

When I push and hold the Murphy Switch then turn the key all other gages except the tachometer/hour meter wont come on. When turning the key to start the engine will fire and run as long as I hold the key in the on position. Can anyone tell me what could be the issue?

 

[blades]

sounds like a bad switch or relay

 

[InnovativeTreeLLC]

sounds like a bad switch or relay

Thanks man I appreciate it taking it to altec now.