i have a 99 gmc sierra with the 5.3L v8 one day i turned the key forward and all the lights came on but starter wouldnt even crank. i checked the battery connections and the starter connections but nothing looked bad. so out of frustration i gave the starter a good whack with a wrench and it worked. the problem has come back after a couple months did the same thing with my wrench and it worked again. now 4 months down the road i have to do it every time i try and start the truck any ideas whats up. i dont want to spend the cash on a new starter if the problem could be something else plus i am going to be getting a new truck soon so i just need it to start up as i try and sell it.