98 Lincoln navigator anti theft blinks truck wont start?

i had the same problem there is no getting around it you have to get it towed to the dealer ship yes they suck :( and they have to reset the comp. this happened to me when i had a street mechanic fix my heater core. even if everything is set up right, and your missing a few vital screws it will cause the theft light to come on because its missing pieces( screws)