I just got new ap1 headlights on my passenger side and its somewhat dimmer then my driver side. What causes this? Is it cause its new ? or i can adjust it ? Driver side is much brighter.

 

check the connections.

 

Hids loose there color and brightness over time. If the replacement light is older than your existing one, that probably why its dimmer. Any time you change hids, your supposed to change both bulbs at the same time.