Headlamps Keep Burning Out


I have a 2002 Mazda Protege, which I purchased used in July 2004. The left headlamp burned out last summer, and was replaced, followed by the right headlamp, which went out last October.

About a month ago, both headlamps again burned out, within one week of each other. My local garage replaced both bulbs, and suggested that the previous bulbs, which had been installed at 2 different auto parts stores, may have been touched during installation, and damaged in the process, causing them to burn out in such a short time. A few days ago I noticed that my left headlamp is out again. Any suggestions as to what may be causing the chronic burnout?



Touching the bulbs during installation will shorten their life, but we must assume the most recent installation was done correctly.

I think it’s time to start measuring voltage at the head lamp bulb socket and checking the connections, including ground(s), in the circuit.

First start the car and turn on the lights.  Now measure the voltage at idle and at speed.  Tell us what that voltage is.


Is there any condensation inside the headlight housings? Water condensation in the left headlight housing of my 2000 Blazer was causing bulbs to fail. I removed the entire housing from the truck and used a hair dryer to dry out the inside of the housing. I then applied silicone at the clear lense/housing joint to seal any cracks.

Ed B.