'99 security anti theft issue, my fix
 

I got the truck from my uncle. Everything for the security system was changed, truck would still leave him stranded. I could have had the computer reburned without the security crap. Instead I got a '96 computer and the plugs for it at the junkyard for $20. I went through wiring diagrams and added the '96 plugs into the harness so I could use either computer if I ever have the original reburned. They are wired different so I did have to connect some wires to different plugs and I had to add power to the EGR circuit as it's fed individually on the '99. I don't have a gas gauge because the wire goes through the '99 computer and I wasn't sure if I could just hook the wire together to bypass the computer as it is on the '96. But it works.

Re: '99 security anti theft issue, my fix
 

I added in a fuse to bridge the fuel gauge wires. It didn't work very well before from what I remember because I couldn't drive it with it dying all the time. We'll see how well it works now and go from there. At least the gauge moves now. You can also see the fuse I added to power the EGR.