Multifunction relay / Fuel pump relay for MERCEDES A working relay, also known as a power relay, is an electrical component that allows a power circuit to be controlled using a low-power control signal. For vehicles with right-hand drive (RHD) For vehicles with left-hand drive (LHD) Refers to the number of pins or wires present on the electrical outlet. MERCEDES-BENZ: 002 545 20 05, 002 545 21 05, 0025459205, 0025459305, 003 545 13 05, 003 545 17 05, 003 545 19 05, 003 545 20 05, 003 545 24 05, 003 545 38 05, 0035450005, 0035451105, 0035451905, 0035452005, 0035452405, A 002 545 20 05, A 002 545 21 05, A 003 545 13 05, A 003 545 17 05, A 003 545 19 05, A 003 545 20 05, A 003 545 24 05, A 003 545 38 05, A 0035451105, A0025459205, A0025459305, A0035450005, A0035451905, A0035452005, A003545240.