After having my car fail to start this morning, I found that there was current going in but not out of my neutral safety switch. My mechanic told me over the phone how I could bypass it (wire from blue to blue with red stripe wire at connector to neutral switch. Car is automatic 89 740 Turbo. Picked up a switch on the way home, installed it, still no start unless I bypass it. What gives? Any light that could be shed on this would be greatly appreciated. Thanks much.

No this was not a trick question. I found the solution. The problem is the the new connector attached to the new neutral safety switch. The 4 female connectors in the plastic connector body were inserted 180 degrees from what the should have been. And this is because the molded in wire numbers on the plastic connector body (1-3 on one side, 2-4 on the other) are on the wrong sides of the connector. This is a Scan-Tech part. Up to this point I thought their parts were okay. I just so happened to notice that the colors of the wires going in and out didn't match. Wires flipped=a car that starts.

Yes...that's always a possibility with the later service parts.
The new neutral start swithes come with a later connector and require 4 new terminals...you remove the old switch and cut off the chassis harness connector and crimp on the four new terminals. But you still have to ensure the old wires go into the new connector correctly.

I did mine backwards...clipped off the connector from the 87 neutral safety switch wiring, spliced them onto the new neutral safety switch (cut off the new neutral safety switch connector) and installed in the car.