Toyota gurus, please help. The tachometer (RPM) gauge of my Hilux diesel 05 model is not working properly. I suspect loose wiring. Checked the back panel of the gauges and so far the wirings are ok. Just want to know where the RPM is connected. Is it connected to the Alternator or the Fuel Injector Pump. Could be that there is a looses wiring at the source.

Thanks in advance for your inputs.