my low beam headlight was out, so i replaced it and it still not working. what may be the problem?

 

Swap the ignitors from one side to the other side and if the problem follows then your balist is defective.. If not then your ignitor is defective.

Assuming you have power at both lamps.

 

CORRECTION

Swap the ignitors from one side to the other side and if the problem follows then your Ignitor is defective... If not then your Ballast is defective.

Assuming you have power at both lamps.

 

just buy the igniter and ballast together and replace on both headlights. The last thing you want to do is this job twice (removing the bumper) like I did. It's about a 3-4 hour job by yourself. Do it once and be done with it. I bought two ballast/igniter combos off ebay for about $55 each.