I?ll double check the circuit board when I get home and I?ll change the wire on the weekend.

Here is a quick recap of events so far:

(1) Installed HFS-3 unit. (+) and (-) input to unit both taken from injector number 2.
(2) Followed the start up guide to the letter. Everything worked as it should in this initial phase.
(3) Moved on to the system priming phase. Ignition to the pre crank position and gauge turned on. As soon as the delay passed and the gauge powered up the system activated and started spraying water.
(4) Tried several times, all with the same outcome. During the times the system was activated and spraying, the bar graph on the gauge never went past 2 bars. This was the same for both pre and post crank position.
(5)When away for a few weeks. Did some head scratching and some research while I was gone. Came Across and few wiring diagrams on this forum which showed the (+) input taken from the computer 12 volt ignition supply. So I changed mine to match that configuration when I came back.
(6) Gave the system a thorough going over. Powered it up and the same happened as I've explained at number 4.
(7) Left the gauge on and turned the ignition off and back on again. This time the gauge didn?t light up as it had done previously. The only light it displayed was the yellow water level LED. The system did not activate and hasn?t since.