I have a 1994 Z-28 that I recently change the starter on. When I tried to start the car nothing happened. The main hot wire from the battery to the starter had power but the wire coming from the key switch to the starter didn't have power at the starter. I ran a wire from the battery junction box, to a in-line fuse, to a switch in the cab, back to the starter. The engine starts normally but will only run few about a 1-2 seconds and then will shut off. What could be the problem?