Hey Scotty, I was working on my 98 Tahoe it was acting wierd took it to Advanced Auto and they said alternator went bad. I bought a new one and put it on in the parking lot. I went to start my truck up and i tripped the security! I've taken it to a few shops including a dealer and none have been able to fix it what should i do? I dont want to sell it as it has 0% rust (i live in northern indiana so its hard to find that. I was wondering if there was a way to tune the security off like you do when swapping an ls motor.

First, try to find a good locksmith in your area as many now work on GM security systems, they bought the equipment. If not, google "bypassing GM security systems" and you will find kits you can buy to bypass those stupid things forever.