I have a 97 chev 1/2 ton with a 5.7. It will not start, fuel pump powers up but no starter. On key on, everything powers up except heater fan, and brake lights are on but go off when I press the brakes.

I checked all realys and fuses, and swapped out starter relays etc. and am stumped. Any ideas?

Did you check the starter itself??

Yes, checked the starter. here's what we found though...

From the alternator, the wire that comes out of the plug on the side, where it links at the first connection that is just on top of the pass side rocker cover. If I wiggle that connection, the problem occurs.

I find this odd, but will chased down schematic and see what is running in that loom. I assume I have a broken wire in that harness somewhere.

Replace the as far back as you can trace that drop. It has likely happened from people hanging the starter from the wiring while removing it.

It turned out to be a bad ground. The ground under the alternator at the block by the timing chain cover had broken off. It always seems to be a ground. Thanks for the help.