Originally Posted by Cab_Burge
The senders, water temp, oil pressure and fuel level read ohms not voltage, amperage or Watts, no current going through them, I THINK whistling scope


Basically the senders have a built-in variable resistor circuit that reads between the 5V and ground..
Since the gas, water temp, oil pressure gauges are essentially a 5V DC meter by adjusting the resistance(ohms) to ground changes the voltage read by the meter..

Just my $0.02... wink