havent posted here in years but i have a 01 SS h/c th350/9" car 61k miles....
it wont crank unless the security light is off and even then sometimes itll shut right back off, the car has some extra wires tied into it that werent original, theres a wire running from the starter relay to a wire under the dash which idk wtf does, it wont crank unless its hooked up. weve tried a new ignition and new key wired under the dash it still does the same thing....im just tired of having to wait 5-10 minutes for the security light to go off before i can drive somewhere

idk if its vats, bad bcm(the radio and windows seem to work fine) or just fucked up wiring, any help is appreciated

 

I looked at his car friday. It would crank and shut off after a couple seconds. Underneath the dash there was a halfass side splice from an added black wire, to a yellow wire in the harness. The harness does not go into the column. one end goes across the trans hump , the other end goes into the big plug up on the driver side firewall beside the brake booster.

The black wire is mysteriously runs from that splice, to the purple wire in the harness and underhood fuse box which turns out to be pin 30 on the starter relay. usually 30 is ground, but i havent had two seconds to take a **** since i left Josh's house friday. someone was supposed to send me wiring diagrams but never did, so that could come in clutch.

The car would only crank if the black wire and yellow wire were touching. I tried touching it to a ground, with no avail, and then a 12v power source and nothing. It only cranks if the two are touching.. Now, to make a more permanent but temporary fix, I cut the yellow wire to make a 3 way splice. In that process, I pulled the starter relay and I touched the black wire to the end going to the firewall, and nothing. Touched it to the side going to the trans hump side and it ran.

I made spade connections there, and it cranked fine until the security light began to stay on. Then I realized that we left the starter relay out, and it was still cranking. So, whatever that means, its bypassing something.. The security light dosent seem to stay on all the time, and for whatever reason when its on, it cuts on and back off.

Im not sure how to COMPLETELY disable vats, i know I can make a resistor bypass for the key, but they've already tried another ignition with a working vats chip and cylinder. So, the problem lies in the module somewhere i think...

Edit:

the wire its connected to in the starter relay is the switched side of power to the starter solenoid... What's the hefty looking yellow wire?

 

Turn off vats in the computer, at least until you figure out your other wiring issue.