been sitting for about 6 weeks. Now it won't turn over. Is it a anti theft issue

turn the key to the run position and leave it on like that for 30 min. make sure your battery can handle this will be a real drain on the batt. most times this works. if that fails then it will be a break in the little orange wires in the steering column. they break from the tilt steering bending them back and fourth over the years. pull the covers off and solder them back together. if the old style aluminium steering colounm you need to remove the wheel, steering lock disk uses a C ring (a real bitch), lift the signal switch off (3 torx and a philips for the hazz and sig lever)move to the side to get access to the tumbler lock, then it pulls out just enough to fix those wires

Vehicle Anti Thief System (VATS) will not keep the starter from 'CRANKING'.. turning the engine over!... It will however keep the engine from 'STARTING' up and running!!