99 crown vic wont crank when i turn the key battery good

Turn key to the run positio, Press on your brake and run your shifter through the gears a couple opf imes then try starting in neutral. This is for the benefit f the neutral safety switch. If still nothing , Raise the hood and and check the battery for a bad or corroded connection. If all is good, make sure car is in park. There is on the driverside fenderwell a relay that looks like a mine Roun With two small terminals and tw large terinals o opposite ides.. When you turn to crank, you put cirrent to one of the small ter minals and that causes the two large battery cables to connect and give power to the starter. If you can jump the battery side cable and the starter side post the starter will crank if nothing is wrong withe the starter.the two large posts. Use a jumper cable,NOT a coat hanger, iF THE STARTER SPINS THEN START IT WITH THE KEY. Good Luck.. Any more help let me know.

The starter relay is the component that the positive cable goes to ,usually near the battery or on the firewall.Cross the relay over by crossing the two larger copper posts with a screwdriver,if it cranks then you need a new starter relay,if it does'nt then you either need a set of brushes or a solenoind,so long as the starter has a good ground[test by putting booster cables between the neg post of the batt and the engine].

Check the connections at the battery terminal and make sure you have >12v. If you have 12v, there's a good chance that it is the starter or starter solenoid.

Put your code in on the door to see if this fixes the problem,if not,when it acts up,lightly tap on the starter with a hammer,while turning the key to see if it starts,if it does,replace the starter.