Cadillac Repair: 1996 CADILLAC DEVILLE NO START DUE TO SECURITY SYSTEM, neutral safety switch, switch jumper

Question
I OWN A REPAIR SHOP AND DON'T DO ALOT OF ELECTRICAL DIAGNOSTICS BUT THIS CAR IS OWNED BY A FRIEND OF MINE AND TOLD HIM WE WOULD GIVE IT A SHOT.THE CAR CAME IN WITH A BLOWER MOTOR NOT WORKING SO WE WENT THROUGH THE MITCHELL FLOW CHART AND CAME UP WITH A BAD HEATER & A/C PROGRAMMER OR ACM (THATS WHAT MITCHELL CALLS IT).IN THE MITCHELL PROGRAM THAT I HAVE THEY TOLD ME IT WAS TO THE RIGHT SIDE OF THE INSTRUMENT PANEL SO WE DISCONNECTED THE BATTERY AND PULLED THE INSTUMENT PANEL LOOKING FOR IT.IT ENDED UP BEING BEHIND THE GLOVE BOX.WE REASSEMBLED EVERYTHING AND WERE NOT ABLE TO START THE VEHICLE AND GOT A MESSAGE ON THE INSTRUMENT PANEL SAYING (STARTING DISABLED DUE TO THEFT SYSTEM).WE PERFORMED SEVERAL RELEARN PROCEDURES AND NO START FLOW CHART PROCEDURES BUT TO NO AVAIL.ONE FLOW CHART DID LEAD US TO BELIEVE THE STARTER ENABLE RELAY WAS BAD SO WE REPLACED IT BUT STILL DIDN'T START.I WOULD APPRECIATE ANY INFO. THANKS

Answer
Hi Steve,

      Electrcal repairs can be frustrateing at times and performing a repair like you did shouldn't have affected the VATTS/PASSKEY SYSTEM. But since it has here are my suggestions.

      1) Double check the areas that you had the dash apart to make sure that nothing was left unplugged.

      2) Disconnect the battery negative cable, turn on the headlamps to drain any remaining power from the computors for 5 minuits. Turn the lights off and reattach the battery cable. This can sometimes reset the computor just like control/alt/delete can with a pc. Then see if the engine will start.

       3) Check that the bat 1 and bat 2 maxi fuses are good in the RH fuse block. Remove the starter enable relay and check for battery voltage from the 2 fuses in the start position. Bat 1 is a direct feed while bat 2 goes through the ignition switch and the neutral safety switch. Jumper 1 of battery terminals at the relay with the terminal that goes to the starter and it should engage with the key on. The last terminal is a ground by the instrument panel because the key is being read correctly when it is turned.

      4) It could just be a coincidence but the 2 wires comming down from the ignition lock cylinder might have picked that time to go open or it has been happening for awhile and the owner forgot to tell you. So disconnect C202 where all the steering column wireing goes and place your ohmeter on the 2 small white wires comming from the lock cylinder. They are white wires with an orange protective covering and aprox. 20ga. Your meter should show a reading. Turn the key 5-10 times from lock to start and see it the reading stays comstant. If the reading goes open when the key is turned you have a wireing problem and need to replace the ignition lock cylinder with keys. Otherwise you can measure the pellet in the key to doublecheck the value and go to Radio Shack and buy a 1/4 watt resistor as close to the reading as you can. Cut the 2 wires and install the reisitor across the 2 wires. Then hopefully the engine will start. There is a 4 minuit waiting period between starts if the resistance is incorrect as a theft prevention.

      Hopefully one of those suggestions will help get to the bottom of the no-start. Let me know if I can be anymore help. Bill