Really strange issue with my ignition hot wire

Alright, I have an 85.5 944 and am using the 14 pin connector for my ignition hot wire (the red with yellow tracer). The wire is energized when I cycle the key forward no problem, but it wont shut off unless I pull up a little on the emergency brake. It will sit and run with the key removed. I've cleaned all my grounds and my relays seem fine, I'm stumped. Anyone ran into this or have any ideas?

I looked at the wiring diagram, but I am not sure why the red/yellow wire would stay hot when key is in off position until park brake applied. You could try getting the key hot for the GM control unit from another source.
I removed the DME relay from fuse box, as it is no longer needed, and used the the key hot from there.
I think it is terminal 85, but not sure, check with test light to be sure.
It is the DME relay that powers up the red/yellow wire at 14 pin connector, so with relay removed that wire would never be powered again.
Hope this helps

Maybe add a diode on the alternator idiot light wire? Maybe its feeding back the ignition switch? Try unpluging the alternator when this happens. If it shuts off when you unplug it, that may be your problem. Not sure why the emergency brake would shut it off though?

The ignition switches fail regularly. I had to replace mine recently for the opposite failure mode.

http://www.clarks-garage.com/shop-manual/elect-17.htm

I dont have anything hooked up to the alternator other than the ls wiring harness, so it shouldnt be that wire (assuming youre mentioning the blue wire in the same plugin as the starter wire).

The car kept running so I pulled the ebrake to get under the hood and shut it off and that killed it. It's also hit and miss now. Sometimes it does work correctly and sometimes it doesnt. I'll try that wire at the relay, I assume it goes straight to the ignition switch? That eliminates any issues with the relay or the wiring after it. If it still acts up Ill try a new ignition switch.

Thank you for the suggestions