Ryanl99c2500
Newbie
Hi all, I have a 1999 gmc c2500, and it has a newer 5.7 vortec that was swapped into it with the matching transmission. Just about everything with it is new, and has been checked. It won’t start, but will crank and run for about 5 seconds or so then flash the security light 3 times. I’ve tried to re learn a key to it with no luck. Does anyone have an idea of what might be happening? I would add a video, but I don’t think I can