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.