I had a subwoofer installed, the next day my passenger side headlight bulb went out, bought new bulbs and installed it and then a few days later it went out again in the passenger side, then the same day the drivers side went out, not sure what happened or what's causing the problem? Would it have been from the subwoofer install?

 

Shouldn't be. I had the same question a few years back, but someone mentioned that the eletrical of the radio and headlights are on different platforms. Could be your ballast going out.

 

Correlation not equal to causation. Check your bulbs, ignitors and 'control units' by flipping from one side to the other and then buy a new one if its the ignitor/control unit. if it's the bulb, buy bulbs in pairs so they match.