I have an '88 Trans-Am 305 TPI. I just need to know where under the dash/in the harness does the starter get its crank signal from? I know it's a purple wire, but I have a few of those and I am trying to figure out why it won't crank over now after having the dash out. I think I missed a wire somewhere, but I can't seem to find it. It started and ran fine before I had the dash out...I have a jumper on the battery as well to rule out not enough voltage.

You might have screwed the VATS up.
Starter wire runs from switch at base of steering column but there are other items involved.Wire does not run straight to starter.

the purple wire is a 10 ga wire. it runs out of the ign switch to the neutral safety switch or the clutch safety switch.

'88, no VATS. I have another harness/connector Im looking at right now seems like the culprit. Hopefully I can figure this out quickly.

Edit:

Alright, I did some more messing with it and found that if I put power from the battery to the 10 gauge purple wire on the "crank" fuse on the fuse panel, it will engage the starter/turn the car over and start the car. So somewhere between the key and that purple wire on the fuse panel is the issue. I really just need a wiring diagram or a trouble shooting tree to figure it out from here. On the other side of the "crank" fuse is a smaller gauge purple wire with a white stripe...I imagine that is what supplies the signal/voltage to the larger gauge wire to crank the car over. So wherever that purple/white wire gets its signal from from the key to it is where my issue lies...

edited with some new/more info...

Have you got power at the starter terminal on the ign switch when you turn the key?