What turns the HIGH speed fan on is the AC switch. When the compressor runs, so is HSF. The temp sensor switch on radiator
regulates its on/off after the signal. ECM 68 operates the low
SF signal. My LSF connector melted and now I get no LS signal from ECM black/green. As far as relays, they can fail in the open or closed position. Shut off your AC and see if fan quits. |