How can you check if the cooling fan relay in the power distribution box is working properly in a 2003 ford focus LX?
Try checking this out first - - follow the fan power wire to the fan housing to where it plugs into the socket located on the fan housing. Remove the plug and clean both the plug AND the inside of the socket completely. A known problem is dirt accumulating in the socket/plug assembly due to its exposed location behind the radiator. After you clean these and re-assemble them see if that doesn't solve your problem. If not - find the proper relay and take it to a GOOD auto parts place and they can test it for you.