1998 Sable will start and drive then after shutting it of won't start not even try to turn over for hours maybe a day then will start right up

When it won't start testing the electrical systems is the proper way to find a fix . Using a DVOM - digital volt ohm meter and power flow diagrams . Using voltage drop testing !
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Electric Testing Techniques You Need to Know
Do you know what a wiring diagram is ? Free wiring diagrams here http://www.bbbind.com/free_tsb.html Enter vehicle info. year , make , model an engine size . Click on engine under system then under subsystem click on starting .Then click on the search button , then on the blue link . This is a wiring diagram of the starter electrical circuit. Do you know what ignition switch is ? the electrical part. , how about the starter relay , transmission range sensor ! There is one thing you can try , move gear selector to neutral an see if it starts then . If that does nothing ,check for B+ voltage going at the starter relay . Jumping pins 30 & 87 at the relay socket , where the relay plugs into . will cause the starter to engage an spin the engine . If you look on the bottom of the relay you will see four sets of numbers 30 & 87 - 30 should have B+ voltage , 87 goes to the S terminal on the starter solenoid . An 85 & 86 are the control side .86 at the relay socket comes from ignition switch through the trans range sensor to the starter relay coil ( electro magnet ) . Watch these videos too .
VEHICLE RELAYS Testing from the relay base

VEHICLE RELAYS Operation Diagnosis