Ok, here's how I think this works. Below is the plug end of an F-Body ignition switch (switch on the left):
View attachment 1715596969
Based on checking for connectivity, it looks like the F-Body splits the power and both the red and the pink wires would be hot.
When the switch is in the run and start position, the red wire connects to the blue wire. Best I could tell, that is the only connection with the red wire.
The pink wire connects to the black/pink wire when in the run position only, while it connects to the yellow wire in the start position only.
The black wire between the blue and the yellow connected to the pink wire, but only when in acc.
The small black wire next to the red wire didn't connect to anything that I could tell.
So, to get this switch to run in my '74 Duster, I would need to connect the following:
Duster -> F-Body Ign Switch
Red -> Red
Red -> Pink
Blue -> Blue
Yellow -> Yellow
<--EDIT
Black -> Black/Pink
Black -> Black between yellow and blue
That would give me a switch that is hot on the blue IGN1 wire in both start and run positions.
The black wire between the yellow and blue wire could be ignore if one didn't care if acc worked on the switch. If it is hooked up, need to look at what runs off the black wire in your car to make sure it doesn't pull too much for the smaller wire.
Hate that the ignition and start/acc power would both be on the same wire then, but that is how the stock system is so at least it isn't worse than stock.
