Additional 2016 Ford Transit Custom security

[Martins V]

Is it possible to Install hidden switch between crankshaft sensor signal wire(or ground, power supply wires) and the ECU so the engine can't be started unless the switch is on.?Or the switch gonna mess up the resistance? 

[Frembrit]

I don't know, but I personally wouldn't want to chance cutting in to that wire.

What's your goal here? To stop someone stealing the van? Might be worth using some sort of visible deterrent first such as a Disklok or pedal locks, at least that way any potential thief might not even bother, whereas if you had nothing then they might break the door lock, steering lock and cause other damage only then to find that they cannot start it.

Alarms and immobilisers can be expensive but is an alternative or addition.

[MarksST]

Better to concentrate on things that stop them getting in to the cab or the back if it’s a van you have tools in. 

[iantt]

Get some decent locks fitted to the doors.