Hey Richard,

In following your instructions, I ran the (+) supply from the injector supply. In the pre crank position the LEDs in the control module no longer illuminate. In the post crank position the green LED flickers, increasing and decreasing as engine speed does. The water level light stayed illuminate in both pre and post crank position for about 5 mins then it went out. There is now no LEDs illuminated on the gauge in either pre or post crank position when the gauge is turned on or off.
I also re tested the voltage at pin 8 in both the pre and post crank position with the same results as before. As per the autronic wiring diagram, the source for the injector positive supply comes from the fuel pump relay. In the pre crank position, this circuit is energized for 5 seconds then cuts out as the engine isn't running. I test pin 8 voltage as so as the pre crank was selected and the reading was 12.81 volts until the circuit de-energized.