I have a 2000 ford f-150 xlt which will not start It was fine yesterday now it just turns over without starting. I have noticed that the THEFT light on the dash is flashing when I switch the key to the on position. I believe my antitheft system is not only keeping thieves from taking my truck but it is also keeping me from operating my truck. I have the two original keys but i get the same results from both. So I disconnected the negative lead on the battery for a few minutes then put it back on and it started.

I let in run for about 10 minutes and turned it off. Then I tried to start it again and it will turn over but wont start and this THEFT Light in my dash flashes rapidly.

I tried disconnecting the battery again but this time it didn't help

Is there any way to fix this without going to ford as i have not had a good experience dealing with their services dept.