car will not start in park on 1992 Ford Taurus

what would cause the car to start only in neutral sometimes and not in park. This is a new development. Once car is started the first time cold. it will not restart again when attempted. Can someone please tell us what could be wrong. It is not the battery. Battery is new and has full charge. It is not the starter cellnoid or starter either. We need help with this, it is urgent

by in Inverness, FL on September 18, 2009
Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
1 answer
ANSWER by , September 18, 2009
Automatic transmission cars have a neutral safety switch to prevent the vehicle being started in gear, only allowing it to start in Neutral or Park. If the Neutral safety switch fails or is out of adjustment the car may fail to start in Neutral and or Park. A wiring diagram is needed to see which of the wires at the neutral safety switch should have continuity and allow power to pass through when the transmission is in Park or Neutral. The switch is mounted on the transmission.