Ducman82

I am wiring in the O2 sensors to a Thunder ECU. I have the 5 wires per sensor wired up, but I am confused on the "MAIN relay +,-, and Ign switch" connections. are they for powering the Heater elements on the Thunder ECU for the o2 sensors? im thing to figure out where to fuse the sensors and if the power is done IN the Ecu? I have the quick start guide, but don't see any comprehensive manuals in the help section. thank you!