I lost the only key to my 98 ford explorer so i went to tye junkyard and got and ignition switch and key from another truck but it didnt work so i tried to program it the way that this say but it didnt work the theft light never stays on for 15 mins it blinks fast for about a min or two then stops i still tried the steps but it didnt work

 

Welcome to FTE.

The computer thinks your trying to steal the vehicle with the salvage yard key it's not programmed to read.
In the instructions you must have missed the need for a minimum of Two keys to reprogram the computer. If you have remote entry, you'll need the FOB's also.

Sounds like you need a good licensed Locksmith, or if you like turning your own wrenches & are handy with computers, you could consider coming by the inexpensive ELM scan tool & running FORScan diagnostic software on the viewing device of your choice, as FORScan is now said to be able to program the computer for keys. I've not tried it yet, so don't have any first hand experience to offer, but you can visit the FORScan website here FORScan How To, to read, inquire & see if you want to undertake this option.

If you decide you want to try & do it yourself & have, or can borrow, or want to come by the inexpensive ELM-327 scan tool, here is a thread where we discuss the ELM & some things to look out for when buying one. https://www.ford-trucks.com/forums/1...-scantool.html
Also look over the FORScan site, as they have some good ELM info you should read before buying.

A bunch of thoughts for pondering, let us know what you decide & how it goes.

 

Which way would work best for a 02 F150?

 

Welcome to FTE.

Follow the instructions for what you want to do in your year model Owner Manual. If you don't have a manual, one can be down loaded at no cost here. https://www.fleet.ford.com/partsands...owner-manuals/