My newly aquired dual fuel XH ute would only run in LHM, cleaning the dirt and corrosion from the two g/box electrical connectors that I cound get to restored normal gearbox operation while running on petrol (thanks to this forum for the info) Eventually found the Apexus petrol start unit which was wired to disconnect the common wire for the injectors was also wired to disconnect a wire that runs down to the g/box. A few minutes work with wire cutters and soldering iron fixed the LHM mode when on gas. The wire is red/white stripe and I assume that it goes from the injector common wire to the gearbox. I have an Ellery manual but the wiring diag. does'nt show any wires of this colour connected to the g/box. Does anyone have any clues, was the original lpg wiring a mistake ? Does the wire go from the injector common to the g/box or is it just luck that I've connected it this way and everything seems to work ok?

Sounds like bit of a Habibi wiring job.
There is 12v that does go to the G/box, usually a red wire, which is power for the solenoids. You should find it on the bigger circular plug. I can't think of any reason why the transmission circuit has been modified, there's no need. The common from the injectors carries 12v, so that would explain why LHM on LPG, as the 12v would be disabled, and enabled on petrol. The 12v power for the g/box originally should come from the ECU, pin 37 or pin 5.

Thanks for the reply. It's still going ok, its good to have a working auto when on gas. Right or wrong as its going ok I think I'll leave it and just tidy up the wiring and redo the s**t soldering. BTW people at Apexus were not very helpful when I phoned then asking for info, whereas people at Gastec (Gore research) not only took the time to answer my questions they put some hand drawn circuits and notes into the post for me.

No probs, injector power comes from pin 57 - which is linked to pins 5 & 37. Why they've rewired is anyone's guess.