Re: JTD Boost Gauge fitment
to get through the bulkhead, remove black plastic cover at bottom of the windowscreen, you will see a black grommit near the passenger side a piller, use this.
you will need to remove your glovebox, poke through something fairly rigid, like an old metal coathanger or a bit of 4mm earth wire etc.
connect to the alloy elbow as I said, use the correct size drill bit and the brass connector will cut its own thread into the alloy elbow, remove, put ptfe tape round and refit, this way it saves a tap and die set.
connect the ground wire to ground, then the positive/ignition/lights wires to an ignition feed, if you put a 500ohm resister in line the brightness of the illumination will be about right, but better to use a 1kohm variable resister and adjust it yourself.