Tech Stuff

Chasing common electrical problems with the Ford Focus

Text & photos by Ken Styer

Instructor, Ohio Technical College, Cleveland, OH

Abnormal instrument cluster operation on the Ford Focus is common
<p>Abnormal instrument cluster operation on the Ford Focus is common</p>

Every vehicle has it fans and its detractors, and every vehicle has its strong points and weak points. While the Ford Focus is no exception, it does soldier on and remains a popular vehicle. That means it will likely come into your shop with its own set of problems. Let's take the shock out of a few electrical problems in this popular vehicle. While not limited to a single model year, you can find these problems on 2000 and newer vehicles. Our photo car is a 2000 Focus Wagon.


Several problems in our Focus appear to be the same or similar, but have very different sources. The driver complaint will be an erratic dash board display. The information display may flicker, go out entirely, partly fail, or create odd displays. While electronic information displays have been known to do all of these things, avoid the temptation to start tearing the instrument cluster out for closer inspection. There are a few other things to check out first.

Our first problem is a bit of a rerun. The old Tempo/Topaz, and several other models shared a similar malady: the alternator connections. If you recall, or even if you don't, the older Fords have a three-wire electrical connector at the rear of the alternator that included the battery positive lead. Due to the fact these consisted of all flat connectors, they would work loose and/or start to wobble over time. This created a poor electrical connection due to a poor mechanical connection.

As the connection deteriorated, it wobbled to the point where the connections would start to arc. From there the connection would deteriorate very quickly. The result was a completely fried connector that usually resulted in an alternator failure and plug pigtail replacement. This was common enough that several aftermarket suppliers included a replacement pigtail along with a rebuilt alternator. You could also readily find them hanging in the parts store electrical section.

While the Focus connector is different, the condition is very similar, but with an added new twist. The Focus connector does not usually cause an alternator failure, but can cause a charging system problem. In addition, it installs gremlins.

With the newer electronics, electrical arcing and poor connections create strange behavior in many electrical circuits. In the Focus, for example, this commonly creates erratic dash instrument cluster operation. Yep, an underhood connection is now creating a dash display problem. The display will come and go, operate oddly, and sometimes flat out lie to you. Keep in mind, with the charging system warning on the dash, there is a direct tie between the two components. Combine that with frequency and rough electrical pulses, and you have the cause of the odd behavior.


While a helper watches the dash, reach behind the engine on the passenger side, and wiggle and twist the alternator connector. Ford calls this a wiggle test, and it is still as good now as it was when it was named. If the dash now behaves properly or gets worse while wiggling, you have found the culprit.

Alternator access can be gained from underneath. Removing the oil filter increases access
<p>Alternator access can be gained from underneath. Removing the oil filter increases access</p>

However, in many cases, you don't need to replace the plug and connectors. You may be able to remove corrosion or tighten up the contacts to repair the problem. Be sure to check for pin fit in the connector. Of course replacement is always a possibility. Don't make the mistake many techs make. Don't just fix it and let it go out the door. Apply the dielectric grease to the connector to prevent any repeat performances of the problem. Dielectric is critical for the longevity of almost any electrical repair on a vehicle. Skipping the dielectric grease will cause the car to come back in the future.

Tags: Ford Focus 
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