OK guys i am not a Mazda owner but trying to help out a friend. Her 08 Mazda 3 has a headlight that doesnt work, even with a brand new bulb. Are there any common or known issues to start with? She says the connector is getting volts, but when the bulb is in, nothing happens.

any direction or insight would be appreciated.

 

sounds like corrosion, a resistive contact (nearly broken wire or corroded contact) could read fine with a meter since it draws no current. but with a bulb in place all the voltage would drop across the resistive part.
I've seen a few issues with corrosion on the PJB (behind the glove box), it could have one wire corroding away and that could kill just one headlight.

 

That just happened to me today, my passenger side headlight stopped working. I switched out the bulb and nothing. try pushing down on the black connector it seemed to work for me.

 

thanks guys. she had someone look at it and found a bad fuse i guess. Apparently a couple of people have already checked the fuses and missed it. either way light is working now, i appreicate the input!