Headlights burn out quickly

A co-worker has a 2005 Pacifica and she says the headlights burn out fairly often. Could this be a bad alternator regulator? How would I check this? What else could cause this problem?

Thanks.

2 things might be happening

1. As you suggest the voltage regulator may have failed, allowing excess voltage spikes to occur. A multi meter hooked up to the battery on a running engine will help. Rev the engine modestly and try turning various electrical systems on and off. Readings over 14.5 volts indicate a bad regulator.

2. However, I suspect the bulbs are being improperly handled when they are installed. The person installing them cannot touch the glass part of the bulb, and not allow it to become dirty or greasy in any way. Any touching, or any fingerprint must be cleaned off with rubbing alcohol.

Such bulb contamination, however slight will dramatically shorten bulb life.