info needed, door trigger

It can't be a wire at the fusebox, that will always be 12V (unless the fuse is blown). I presume you have swapped inputs (ie, tried +ve trigger).

Peter it can if there's a processor/timer involved, all Toyotas and VW Golf/Jetta, Fiat Punto Hondas at least, top of my head work this way.

Your experience outranks my theory. I'd be curious how (unless I misinterpreted) - sensing IMO would have to be current, hence an inserted shunt or loop sensor unless comparing voltage drops between processor +12V and the downstream fuse end. There are other methods, but I didn't think they'd be used (ie, requiring processors, but since they are now being used, maybe products have finally caught up with "old" methods...?)

I'll email you on this one Peter.