Need help figuring out anti theft

Hi. I have a 98 GMC Sierra, 4.3 liter

The ignition was busted on a attempted theft.
I've replaced the steering column and ignition cylinder with one from junkyard.

It will crank but will not run

I have correct fuel pressure, I have correct spark. If I put starter fluid in the throttle body it will run until the fluid runs out whilst the security light flashes. Leaving me to believe it is an anti-theft issue. When i turn the key to the on position the light only comes on for a few seconds then goes off as i believe it is suppose to. Here's what I have tried so far:

I tried the "relearn" trick that if I did correctly, consisted of trying to start, letting the key sit in the on position for 10 minutes, switching off for 5 seconds and repeat 4 times. The only thing that was different from the posts I've seen was during this my security light never came on, it only comes on for the previously stated few seconds when key is first turned and in all the posts I read the light stayed on

I've tried tricking the security system. I seen a post where by clipping the yellow wire from the 3 that runs to the cylinder then putting a resistor between the yellow wire and orange wire with a black stripe it will trick it. I tried this and my security light now flashes consistently while it is hooked up this way.

I'm in dire need of my truck and can't work without it and am now turning to here hopefully to find answers. I have no money to pay someone else to do it. I will respond to all suggestions and afterwards if a suggestion does the trick I'll be sure to post that it did. Thank you for reading and your time

Your BCM is wanting the resistance provided by the key chamber from your old steering column-- if it still available, it would be good to read the resistance of it and then find a resistor to provide that to your BCM. You can also use a variable potentiometer, and experiment until it starts- by tweeking the value of resistance until it finds the right value-- this will take awhile, but may be worth it. Other than that you can re-learn the new resistance by using a Tech II scan tool

I still have the old column. How would I go about finding the resistance? I have a multimeter, not much past that for reading such things.

I got it. There are several post talking about putting in a resistor to match the resistance of the ECM and insert it to complete the loop. I got my reading with a multimeter by touching my stripped back black wire and either the yellow or orange one on the ignition that runs to the security box. I got a reading at 621 Ohms. The closest I could find to that was at RadioShack and was a 680 ohm resistor. I clipped the yellow wire entirely and stripped back the orange one. I crimped my connections. One end of the resistor went to the orange and the the other to the harness side of the yellow. At this point when I turned the key over to the on position my security light flashed so I let it sit and proceeded the "relearn" instructions. After the 3rd 10 minute wait it fired up