Transmission start lockout

Hi, I'm new and I tried searching for this but didn't see anything, so I apologize if its has been covered. I have an 89 Wagon LE V6 and it is having issues. You know when you try to start the engine when the car is in Drive or anthing other than Neutral or Park, it won't start. Well, I think that switch is messed up, as it is not starting sometime when in Park or Neutral as well. I run it back and forth through all gear positions and wiggle the shifter and it eventually will start. For now. Does anyone know if this is a common problem, where this switch is, how to fix, etc.?

Might be your starter contacts. They will fail and give you an all or nothing start. Common problem and a cheap fix. If you only hear a click when you try and start it, it is likely the contacts.

http://www.off-road.com/toyota/tech/starter/

http://www.automotiveforums.com/vbulletin/showthread.php?t=166530