Have a 2001 focus se. Neither the main cooling fan or the AC fan will come on, which causes overheating in stop and go traffic. The fans work, as I have put 12 volts to the fans directly. Fuses are good.
Question is how can I troubleshoot the relays, sensor, fan resistor assembly, etc. without using the shotgun approach? The Haynes diagram is okay, but not enough info to troubleshoot.