Hi guys, bought a factory LPG falcon AU ute a week ago. Found it odd it had a switch to engage/disengage the cut-off to the tanks.

Had a look under the bonnet and he's poorly wired in a switch from the 12v cutoff solenoid on the converter to the loom, essentially bypassing it manually when i start/stop the car. Dangerous for a number of reasons as I'm sure you can imagine.

I've tried to rectify it..

-Connected solenoid as per stock - no go - maybe broken solenoid?
-Bought new solenoid and pin - connected them - but gas tanks never engage
-Bought new wiring look for the converter (3x 2pin plugs, 1x3pin plug, 1x4pin plug) - connected it all up but still no go.

Don't really know what else I can do?

When the switch is wired in to the positive(+) of the 12v cutoff solenoid, it functions fine (by the switch), however, it doesn't seem to work at all without that switch.

Is there a fuse or relay im missing here possibly?

Being a dedicated gas engine there should be an lpg relay and fuse, when the engine cranks the pcm will supply the ground to energize the lpg relay when it receives a crank signal from the crank sensor.

This will then close the main relay contacts and supply battery pos to your lock offs and tanks. Get your self a wiring schematic.