i have an '89 vert that has rear end damage. the trunk will not shut anymore. it won't start in park after the incident. it'll start in neutral but not park. is there some kind of security/safety switch in the trunk latch? i noticed when i turn off the ignition the security light flashes now but didn't do it before. any help would be appreciated. thanks

 

Since you said park, i am guessing this is an automatic.

It could be possible the shifter is no longer "landing" properly on the park position due to the accident. The transmission could of shifted place (moved forward since it got rear ended) and now the shifter cable is improperly engaging the gears. This is one possibility and if it does happen to be this, most cars have an adjuster for the linkage, I don't have an automatic FC so this is something you would have to check. Is it hard to move the shifter up and down now? Also check the wires to the transmission.

The security light flashing, is due to the truck alarm sensor thinking the trunk is open. I tried this out on my vert just now and it will not flash if the truck is close, but will when the truck is open.

 

Unplug the two connectors for the inhibitor switch and check continuity on park mode. A & B are the starter lockout if memory serves correctly, and those two wires(on the 3 pin plug) are only connect in P and N ranges. Technically you can connect A & B and the car with try to start in D mode.

*edit*

here is the pinout for the different ranges via the fsm.