1997 Taurus - Won't Start - Enigma

My husband's Taurus won't start. It does not crank or turn over. He connected directly to the starter with success, but as soon as he releases the key to the on position, it stalls. He has had the starter tested. He says the battery is good. Also, we tried to shift the car into neutral to push it more into the drive, but it wouldn't move. The followling has been replaced: the neutral safety switch (NSS), the ignition switch, the ignition cylinder, the starter relay fuse. He says the battery connections and starter connections are good. He told me that there is no power the the NSS. What could this be??? Any help would be greatly appreciated.

Will it start and stay on if started in the neutral position? I only have the schematics for a 95, but hopefully they are close enough for me to help you. The Neutral Safety Switch,NSS, is not in the start circuit, but the Transmission Range Sensor, TRS, is. Power comes from the engine compartment fuse block, to the ignition switch, to the TRS, to the starter solenoid. The NSS should power at all times from the inside fuse panel fuse 1, which also feeds the multifunction switch, the hazards and the signals. Either you have a blown fuse or a wire disconnected. I seem to recall having problems with that switch down on the brake pedal arm where some knucklehead routed it so that it rubbed through from braking and then shorted out, blowing a fuse. However, I don't follow the relationship between the NSS not powered and the engine not staying on. Do the brake lights not work, as would be the case with no power? No power to the NSS also would prevent you from shifting out of park while the key is in run.

With all that's been checked and changed and it shuts off when started and put in run, sounds like a ground problem. If the battery is clean and well connected, then the ground wires and their connections to the engine and body may be loose or dirty. I once had a mysterious engine cutting off problem while driving on the Interstate that happened infrequently just out of the blue. It would just die quietly and suddenly and I would drift to the side of the road. Turn everything off and I could start it right back up again. I finally was able to trace the problem to an imperceptibly loose ground to engine connection, but that fixed it!

Then you could have an ignition system problem. Maybe coil not grounded/secured enough? I'll let someone else jump in.

Welcome to the forum!

Also, we tried to shift the car into neutral to push it more into the drive, but it wouldn't move.
Which wouldn't move, the shift lever to shift to neutral or the car once shifted to neutral? I suspect the former, and think tripletdaddy is on the right track with checking the brake lights. The stop lamp circuit controls the shift interlock which would prevent shifting out of park without having your foot on the brake pedal when that circuit's working properly.

I'd suggest checking the inputs and outputs for the ignition switch, which it sounds like has already been replaced. Were any of these items tested before replacing? Do you have a service manual for the car? You'll probably need the wiring diagrams to determine what is and what is not working properly in the starting circuit. It looks like power to the ignition switch for this function comes from fuse 3 (40 amp) in the engine compartment fuse/relay center.

I'm not clear what he did when you type he connected straight to the starter but it stalls as soon as the key is turned to On. Are you saying that the starter motor would spin the engine when but the engine would not start, even with the key in the Run position? With the starter shorted to battery, was someone holding the key in the Start position? Did the car start this way, but as soon as the key was released to the Run position the engine would stall?

You can find a wiring diagram for the starting circuit of your car available for viewing free at the AutoZone website. There is a fuse between the ignition switch and the Transmission Range Sensor. Maybe that's the reason "there is no power the the NSS." This line would only have power though when key cylinder switch is in the Start position of a normally functioning starting system.

-Rod

"Which wouldn't move, the shift lever to shift to neutral or the car once shifted to neutral? I suspect the former, and think tripletdaddy is on the right track with checking the brake lights. The stop lamp circuit controls the shift interlock which would prevent shifting out of park without having your foot on the brake pedal when that circuit's working properly."

The car wouldn't budge. It was as if the car didn't shift at all.

I'd suggest checking the inputs and outputs for the ignition switch, which it sounds like has already been replaced. Were any of these items tested before replacing? Do you have a service manual for the car? You'll probably need the wiring diagrams to determine what is and what is not working properly in the starting circuit. It looks like power to the ignition switch for this function comes from fuse 3 (40 amp) in the engine compartment fuse/relay center.

"I'm not clear what he did when you type he connected straight to the starter but it stalls as soon as the key is turned to On. Are you saying that the starter motor would spin the engine when but the engine would not start, even with the key in the Run position? With the starter shorted to battery, was someone holding the key in the Start position? Did the car start this way, but as soon as the key was released to the Run position the engine would stall?"

Please forgive my lack of auto terminalogy, but he 'jump started' the car right at the starter. Once the key was let of, into run, the engine stalled.

"Will it start and stay on if started in the neutral position? I only have the schematics for a 95, but hopefully they are close enough for me to help you. The Neutral Safety Switch,NSS, is not in the start circuit, but the Transmission Range Sensor, TRS, is. Power comes from the engine compartment fuse block, to the ignition switch, to the TRS, to the starter solenoid. The NSS should power at all times from the inside fuse panel fuse 1, which also feeds the multifunction switch, the hazards and the signals. Either you have a blown fuse or a wire disconnected. I seem to recall having problems with that switch down on the brake pedal arm where some knucklehead routed it so that it rubbed through from braking and then shorted out, blowing a fuse. However, I don't follow the relationship between the NSS not powered and the engine not staying on. Do the brake lights not work, as would be the case with no power? No power to the NSS also would prevent you from shifting out of park while the key is in run."

That's why we replaced the NSS. Since we could not get the car to budge in neutral, we assumed (I know, bad word) that the NSS could be bad.

So when he "jumped" straight to the starter, was someone holding the key in the Start position? If the key was not in the Start or Run position at that point, the engine should never have started since the PCM would not be enabling the fuel pump or ignition system.

If when shifted to Neutral the transmission seems to be stuck, potentially in gear, I would suggest you get the wheels off the ground and safely support the body of the car, then chock the rear wheels. I'd hate for you to find out that the transmission is stuck in gear, then get pinned between the car and something else when the starter motor decides to work and move the car.

-Rod