This just blows my fuse...

[overtimeracing]

Hey guys... I hope you can help me. My mother (73) has a 96 S10 Blazer. She resently had the engine replaced with a used 4.3 from a local guy. She drove it for about 2 weeks with no problems. One morning I had to move the Blazer so i could work on some of my junk. Started it, moved it, and parked it. Later I was going to go to the parts store, so i thought i would take her Blazer and it wouldnt start. Wont even crank. Tried to jump, with no luck. I guessed the starter was bad, so I brought it into the garage and replaced the starter. No change. My buddy told me to check for a blown fuse and sure enough, there was a 10a fuse marked crank, blown. Replaced the fuse, and it started... once. Now it continues to blow fuses, and wont start. I pulled the start wire (purple) and checked its condition and it seems o.k. (I expected to find it burned to the exhaust manifold but no such luck.) Even disconnected from the starter, it still blows the fuse. I've followed the wire up to where it goes into the large harness. Nothing seems crimped, burnt, or broken. I dont know what to check next. I hope someone has experienced this before and can help. Thx...OTR