Cadillac Repair: 1997 deville northstar v-8, negative battery cable, wireing diagrams

Question
hi bill,  today i went out and started my car and when i put it in reverse everything went dead. no dash readout no nothing.wont turn over etc. power seats still work,lights work, everything that would work without the key on works.when i turn the key on it acts as if i didnt.im a mechanic with many tools but these cars are pretty tricky. can you help.

Answer
Hi Scott,

     That sure is a strange thing that happened. Getting to the bottom of this sounds like you will need several wireing diagrams.

     I'm sure you have already checked the battery cables for tightness. Also that the battery has 12 volts. The negative battery cable where it attaches to the LF of the engine near the RH radiator end tank has been known to loosen up. Make sure it is tight. Near the LF strut tower there is a fuse/relay junction center. Make sure the positive battery cable is tight where it attaches to the panels and has battery voltage. Make sure all the fuses are good useing a voltmeter or test light.

     Then go inside the car and test the ignition switch for power in and out of the switch on all the wires. Sometimes the ignition switch can have bad contacts and not allow 12 volts on one of the wires to the computors and that will shut things down in a hurry.

     If there was any area of the car that was worked on recently go over that area and see if you can spot anything  loose or disconnected.

     Try those things and let me know what happens if you need anymore help. Bill