I'm building a custom digital dash so I'm wondering if anyone knows what each gauge uses as an input (voltage, resistance, etc). Obviously the voltmeter reads voltage, the fuel level reads 0-90 ohms resistance, any ideas on the others?

 

Oil pressure is measured in OHM's the same as fuel, "0" is low and "90" is high. Coolant is also measured in OHM's, 55 OHM's will equal about 260 degress where 1400 OHM's will equal about 100 degrees. In this case the higher the resistance, the lower the temperature. The tachometer operates off a voltage frequency pulse from the ignition system.

 

Thanks SO much. I'm doing bargraph style gauges for the temps so that will help alot. I'll probably buy a speedo and tach and make my own custom bar graph around them. Any idea how the speedo works? Constant voltage I'm hoping!