1997 Honda Civic motor turned off while driving had power m

my 1997 civic already had bad oxegyn sensor i know that. my car would sometimes drop speedometer really fast 0 then back to original speed. recently my car shut off on freeway going about 70mph,my ligfhts stood on as well as stereo just motor shut off. i started down shifting into fourth poppping the clutch finally motor kicked on. i changed fuel filter car stated fine immediatly after. i unplugged a wire connector connected next to fuse panel tried to start car no response.I was trying to disable car, live in rough area.Plugged connector back in now car wont start. I cant hear fuel pump and when I turn key to on no lights on dash come on. checked fuses there all fine. car crank but no turn over.I notice a black wire coming from fuse panel tapped into fuse labeled security. could this be some kinda bypass for kill swich? this car has no alarm system, that i know about.