Hello to all,

I have a 1996 Fleetwood Brougham.

The nose of the starter snapped. Looks like it was not shimmed properly.
Went to NAPA and purchased a new starter. While reconnecting the battery, the starter very briefly engaged.
No key on. Went to try starting and the digital display goes blank and starter does not crank. When I release the switch from the start position dash returns to normal readout. Battery voltage was 12.4V. All connections are clean and tight. I have bench tested the starter twice and it works fine, just not when it's installed on the car.
Also I have checked the fuses in the I/P and under the hood. All good. I checked for codes and none are displayed.

My questions are the following:

Could the temporary bump of the starter cause the control module(s) to fail?

Could this be an anti-theft system problem? (The anti-theft light on the dash lights for 3 seconds and goes out when the key is turned to the on position.) The GM manual states that as normal. What else can I look for?