2007 GSX750F tachometer not working. I need some help to diagnose why tachometer isn't working all other dash instruments work it's only a tacho problem. All fuses under the seat are ok. I need to know where it gets it's pulse from and it's location also wiring color so I can trace from the signal source to the tacho to check for broken wires or corroded plugs etc. Any suggestions and a wiring diagram will be great thanks.