DelCoch has hit it rite on the head, Next time it's in the crank but no start mode, turn the key to the on position and listen for the fuel pump whine, no whine means no start, You will also notice that the dash cluster will have no idiot light's lit up either....
You have a bad Ignition wireing harness on your 1997. It was a VERY common problem on the 97 model's. Replace that harness ASAP before it dies out in traffic and someone slam's into your truck.