... is off position) press A on the transmitter, receiver A goes on 2seconds,then goes off automatically.same ... D.3) interlock modelPress remote button A, the receiver relay A is on, the relay B/C/D ... is off.Press remote button B, the receiver relay B is on, the relay A/C ... /B/D is offPress remote button D, the receiver relay D is on, the relay A/B/ ... and fix code(eg.kl-400)12V 6-channel remote control switch