How to Replace the Wiper Power Relay in a Ford Focus

Disconnect the battery. Unlatch the cover from your Ford Focus' engine compartment power distribution box that houses the wiper power relay.

Pull out your wiper power plug-style relay located in the center of six medium-sized blocks at one end of the box (labeled as the 31C block on your power distribution box diagram).

Check the box area for any dirt, corrosion or damage that may have caused the relay to malfunction and clean or repair any area as needed.

Push your replacement Ford Focus wiper power relay firmly into the empty relay socket. Remember to check that the relay isn't loose, as current running through a loose relay can cause the relay to overheat or the outer casing and surrounding relay casings or box cover to melt.

Return the cover to the box and reconnect your battery. As your Ford Focus has an adaptive learning computer, you must reset the computer before testing the relay.

Reset the computer by following these steps: set the parking brake and gearshift to park, turn off all accessories, start and then idle your engine for at least one minute, turn on your air conditioning and continue to allow the engine to idle.

Test the wipers to see if the relay corrected the malfunction. If they work, continue with your computer reset by driving your Ford Focus at least 10 miles (to help the transmission relearn). Finally, reset the clock and radio presets.