Electrical Relays

Various relay combinations are used by model application. However, most common relays are main relay which activates the ECU, injector circuit and starting circuit when ignition is switched to start mode and fuel pump relay which activates fuel pump during engine start mode and is then controlled by air flow during operating mode (except Datsun models). Datsun models are equipped with a fuel pump control relay which monitors engine oil pressure and alternator output for deactivating fuel pump upon engine failure when ignition switch is left "ON".