1994 Cadillac Deville won't srart

Disconnect both positive and negative battery cables and touch the cable ends together for 5 mins to see if anything changes. This procedure depletes the energy stored in the computers. Essentially resetting them.
As for the no start you may need some one tapping the starter with wood handle or hammer because the start may have what is called a dead spot where not enough energy can flow but tapping the start with a hammer or handle will dislodge the start from the dead spot and cause it to start. Make sure the battery cables are tight on the battery and at the starter and that there is no corrosion at these electrical connections.
Thanks for the question