Removing the accessory belt tensioner on the Ford Focus requires the removal of only one bolt. The tensioner is critical to proper operation of the belt as it keeps the belt tight on the pulleys that drive your alternator, water pump, power steering and air conditioning compressor. If the tensioner is not working and the belt is allowed to slip, it will not turn the accessories efficiently and the belt may glaze and fail early.
Remove the negative battery cable from the battery and set it aside for now. Place it so that it can not fall back against the battery until you are ready to reinstall it.
Place a ratchet with no socket on it in the square hole that is in the lug at the far end of the tensioner. Turn the ratchet counterclockwise and release the tension then slide the serpentine belt off the tensioner pulley. Slowly release the tensioner and remove the ratchet.
Locate the bolt in the tensioner arm on the end away from the pulley. This is the mounting bolt and it threads into the engine block.
Remove the tensioner mounting bolt using a socket and ratchet. Pull the tensioner straight off the engine. Leave the belt laying across the pulleys to allow for an easier reinstall later.
