I'm in the middle of putting a simple ignition cutoff switch in, but I'm stuck.
In the chart above the dark blue should be the wire to cut, right?
On my XJ it's black orange... the only one that gets power with key on and power off with key off.

Do I have to cut one or both for a switch?

Quick help would be greatly appreciated, the dash is apart at the moment...

Cut them both & use a DP switch. BTW, very few steal vehicles via "hotwire"anymore. If it's actually rare and valuable enough to steal then a flat bed or a tow rig and dollies is the tool of choice. Easy money pop the window stuff: GPS units and $$$$ head units, subs. Cut & grab stuff: cats and airbags.

I gotta ask, why both?
thanks

I had hoped cutting the power to the TCU would leave some fool trying to get it it go out there, revving the motor and not moving. No luck. the AW4 will go anyway. Guess if the fuel pump power was switched off, there might be some noise...doubt it'll go far go far that way though.

I used the blue wire.
Used mainly to dumb thefts...
and to prevent friends from messing around.

??? So they can't operate the drivers window? Intrusting logic. (I've known sneak thieves that should endure their own stench.) Another one, available are mongo switches for the battery to starter cable that take a (simple), key like deal to connect/disconnect. I don't like it, messing with that current. A good friend who's no dummy has one down under the bumper of his custom 10,000 lb.GWR/camper/van..was a frig-van. Cool custom chevy diesel....Yer not likely to get her goen if you don't find that. (he's a musician who makes custom instruments, his work on the camper/van is pretty slick)

I'm not very familiar with your 99. Freedgr and TJ amongst others may know where to put a switch that will let it start, then die a couple of secs after the key is let up. ..Or you got it, something that works?