I have a 1990 cadillac deville, it was running great and one day just would not start! Any Ideas why? Neutral safety switch has been checked and replaced also computer, new battery, and the ignition switch, ignition lock cylinder is being replaced now. Thanks

You can check on line from the different parts stores of visit your neighborhood store. They will probably need to order it. A Cadillac Dealership may have one in stock.

Did you move anything to remove sensor?Check connection if you plug right.

Not a difficult job. The switch is mounted on top of the steering column near the floor. There is a screw on each side that holds the switch to the column.

Might be the neutral safety switch. Is the security ligt blinking?
Do It Yourself Diagnosis and Repair

If the security system was the problem the light would be flashing in the dash indicating activation and lock out.

No, not that switch, but the brake light switch on the brake pedal. It may just need adjusting to turn off when brake pedal is not pressed.
The neutral safety switch is in your starting circuit to keep car from starting when not in park or neutral.

Welcome to FIxYa.com

Check the battery wire to starter with a volt meter is there 12 volts? if so check neutral safety switch. Place trans in neutral will engine start now?

Thank you for using FixYa.com

Regards, Lee Davidian

So you have no crank no start correct. Three possible items to check : ignition switch,neutral safety switch, starter relay. and if applicable starter interrupt relay.

I would first replace the FUEL FILTER. If problem persists, make sure exhaust is not partially clogged like a clogged catalytic converter. Hope this helps

The neutral safety switch is on the top of the automatic transaxle (under the hood). You have to remove the air cleaner assembly for access to this item. Once the air cleaner is off, you can see the switch mounted on top of the transaxle.
Remove the shift linkage, electrical connectors and vacuum hose as needed.
Remove fuel line bracket if needed.
Remove mounting bolts and nuts to remove the old switch.

Install new switch as reverse of above.
Put shift lever in neutral.
Align switch so it's alignment hole and the matching tang hole line up. Tighten down the switch mounting bolts. Verify that the engine starts in PARK and NEUTRAL. Re-adjust if it doesn't.
Charlie