• Introduced in the 2000 model year, the Ford Focus is an entry-level vehicle designed to replace the popular Ford Escort. The Focus earned the distinction of most recalled vehicle in Ford Motor Company history in its early models; however, later models vastly improved the Focus image. One of the recalls issued was directly related to battery cables issues with the 2000-02 models. One of the more common trouble spots with the Focus is the battery circuit.
  
  

Loose Connection

• Over time, the battery cables and their connections to the battery, alternator and ground points can vibrate loose, to a certain extent. In other cases, an absent-minded oil-change mechanic can fail to tighten the cable properly after cleaning the cable ends and battery terminals. In the event you believe you are having battery cable issues, often heralded by slow crank on start-up (or worse, no crank on start-up), the first thing you should do is visually inspect the connections and tighten as necessary.
  
  

Corrosion

• If your Focus battery and cables are not properly maintained, corrosion from the battery can infect the cables and connections. In extreme cases, the corrosion can build up a layer between the cable and the battery, preventing the two from making clean contact. This corrosion is acidic and will eat away at the battery cable ends and the cables themselves. Once your cable is infected with corrosion, it is only a matter of time before you will have to replace it.
  
  You can clean the corrosion away with a good battery terminal cleaner and a wire brush. Make sure to use safety glasses and mechanic's gloves when performing this, as you do not want to get any of the corrosive material on your skin, or worse, in your eyes.
  
  

Broken Connection

• As your Focus gets on in years, the battery cables can begin to weaken after thousands of hot/cold cycles (from the engine warming up to operating temperature, then cooling back down, day in and day out), or due to being removed and reinstalled one time too many. If this is the case with your Focus, inspect the cables and cable ends for breaks in the wiring or ends. If there are any broken wires in the cable core or broken metal in the cable ends, chances are your Focus cannot access the electrical energy it needs from the battery and alternator. If you discover any breaks, replace the cables immediately.