[Nahkapohjola]

Max-93 has a separate switch near the handbrake, maybe -98 has not?

Wiring harness can be opened and traced only by opening all places where the bundles seem to go. That is, if no wiring diagrams are available. Lot of work. Or you can add a new wire from some place near fuse panel which is hot when u want, say -ign on-.

Btw. Purchase a 5$ tester with a pin that penetrates wires. With that it is easy and fast to troubleshoot and to check which wire is hot.

What you should be getting to that back connector, is +12V always, and another +12V only when ign is on (=antenna up signal) plus gnd.