anti theft light flashes

Hello, I'm Danny.

Let's first start with an anti-theft, security system reset. Here is the tutorial:

https://www.2carpros.com/articles/how-to-reset-a-security-system

Let us know what happens and we'll go from there. Hope this helps and thanks for using 2CarPros.

I've tried all five of these steps in "the how to reset the security system" to no avail. If you can come up with anything else I'd sure be thankful. Thank you for your time and attention.

It's very possible that one of the connections for the system isn't fully connected or a pin was damaged during the repairs. To avoid tearing it all back apart I would take a scan tool and see if you can talk to the anti-theft system and see if that one will register the various steps that disarm it. Like, key in lock, key to run or start, then see if it shows anything like a communication fault. Isuzu used a mix of GM and their own parts on those and they are rather finicky about the scan tool they will talk to, a Tech2 will work but some of the clones won't.

Hello again.

Yes, I agree with Steve on using a GM Tech2 scanner to test the anti-theft system further. Those scanners are getting harder to find but are out there. Maybe you know a friend who can loan you one? I've attached a picture below of what it looks like and what they're going for on EBay. Hope this helps and thanks again for using 2CarPros.

Danny-