Anti- theft system

I believe you can reset the anti-theft system by unlocking the driver's door with the key, then turn the key in the ignition it's full travel until theft light stops blinking and then start as normal. When your son replaced the steering wheel he inadvertently removed or disconnected the transponder in the steering column. That transponder needs to be reconnected or the system will remain activated. (The transponder is the sensor that interacts with the chip in the key.)

KenF thank you for that, however the driver's side door lock does not work nor has it since we've had the truck, so with that said is there anything else I can try to get it to start?

ok, well that is a 1-2 whammy lol. You can pop the driver's door panel off, exposing the locking rod from the outside lock to the locking mechanism. Then sit inside the vehicle, lock it as normal, then reach inside the door and tug on the locking rod to unlock it. It will have the same effect as unlocking it with the key from the outside. I strongly recommend having your son search online for an owner's manual for your truck (if you don't already have one), it will have procedures for resetting anti-theft. I'm going by memory on some of this so there may be another way to deactivate anti-theft. I'm also assuming you have a proper master key and not a valet copy. (The master key has the transponder chip programmed to the vehicle.)

Thank you, I have a manual. I also have a key that came with I honestly don't know if its a master but I also made a copy that "used" to start the truck just fine.. I will look into it and have him try your suggestions. Again thank you very much!

My 97 expedition was running good then one day it died and know it wont start theft lite blinka

1998 Ford explorer. Theft light blinking on dash will not let car start. Can u please help. I have disconnect battery cable. Took key to unlock driver Door car will not start