Make up a jumper wire , 10ga., about 10 ft. long w alligator clips at each end. Next time it doesn't start , set the emergency brake, put in neutral, turn the key to on , pop the hood ,connect one end of the wire to the + terminal of the battery and CAREFULLY touch the other end to the solenoid contact (small wire terminal) on your starter. If it kicks right over you have low voltage to the solenoid, poor battery condition , bad ignition switch , corroded/broken wires, worn relay or a combo of all. I just carry the jumper in my glove all the time. Got me out of a jam on many hot days.