JustAnswer Blog: Automotive

You are here

Why do my Grand Vitara's headlights keep failing?

(Photo: Flickr/JeanbaptisteM)

Why do my Grand Vitara's headlights keep failing?

July 03, 2012

Daily Answer is excerpted from the JustAnswer archives and features information provided from a Expert on JustAnswer.

Q: My 2008 Suzuki Grand Vitara blows out its headlamps often and now my low beams don't work. I've replaced all four head lamps and the fuses are OK. What's the problem?

A: This sounds like you may have a bad alternator which is over-charging (putting out too much voltage). The headlights are always the first to go because they are the weakest link in the circuit.

I would start by having your alternator tested. You can do a quick check yourself if you have a digital volt meter. With the car running, measure voltage at the battery's positive and negative terminals. A normally operating alternator should fluctuate around 13-14 volts. If you get a reading over 14 volts then your alternator's voltage regulator is bad. You will then need to have it rebuilt or replaced.

-- Answer from Paul C., a master auto technician on JustAnswer.

Other car questions? You can ask a mechanic on JustAnswer, at http://www.justanswer.com/cars