where is this switch located on the tranny (68 c4). my car can start in all shift positions and i suspect the switch and/or wiring close by.

 

I think tt's on the left side of the tranny, near the kick-down.

On the firewall, there are some wires that go to the Oil Pressure & Water Temp sending units, and another set of wires going down to the transmission. Just follow those wires.

 

It is mounted on the tranny, over the shift lever.

Sounds like the thing is bypassed because it had a problem.