I have a 2006 Chevy Trailblazer EXT with the 4.2. The engine spun a bearing, so I grabbed an engine from the local salvage yard. The only thing I replaced, was the short block itself. I used the original wiring harness, starter, alt, a/c comp, ext. Once I got everything back in and hooked up, I went to hook up the battery and the starter kicked on with the key in the OFF position. I have checked all my hook ups, grounds, connectors, fuses, relays, and everything looks right.

Any ideas?
Brett 325-669-6942

 

make sure the wires on the starter are not touching somehow and are not hooked to the same post

 

Everything may look right, but obviously there is a wire that is hot all the time hooked up to the wrong post on the starter.