Lucky you managing to get yours to run again. I'm currently fighting with mine too.
It's quite possible you have installed the same as I have in mine (2001 Wagon). Mine is a Ford 'System 4' Dealer installed add-on alarm system. Probably the same 125dB siren under the hood (behind LHS headlight) and on my dash (in a slightly different position) is a lighted push-button 'valet switch'. It is operated using the standard Ford fob. They seem to have been very commonly installed on lots of different Fords. The PN on my control box is LBL0436.
My system (in a recently purchased car) seemed to be working fine. The PITA feature was that even if the car wasn't locked or system armed, in order to start the car it was necessary to lock and unlock the doors with the fob.
Last night I decided to try and program a spare fob. Well, I got that part wrong and managed to de-program my fobs and also the alarm got armed and all hell broke loose! 125dB is VERY loud when you're frantically trying to disconnect the battery which is right next to the siren!
I've managed to reprogram 2 fobs that will lock/unlock the doors and apparently arm/disarm the System 4 but when I turn the key to start the motor nothing happens. I've tried locking/unlocking the doors (like before) with no success.
All this time the OEM alarm light (next to the Hazard switch) keeps doing a slow blink. This is my first experience with a Focus, so I didn't notice what this light did before yesterday. Is this normal in Focii with no alarm system added? I'm not sure if I'm fighting 1 alarm system or 2 at this point! Is there some way to do a 'reset' for the OEM system?
Help! And TIA.
P.S. My first post.