The 1-1703639-1 is Power Relay K series from TE Connectivity are through hole automotive relays. These relays are used in ABS control, blower fans, car alarm, cooling fan, engine control, fuel pump, hazard warning signal, heated front screen, heated rear screen, ignition, lamps front/rear/fog light, interior lights, main switch/supply relay, seat control, seatbelt pretensioner, sun roof, turn signal, valves, window lifter and wiper control.