• The headlight fuse is blown. Double-check either by inspection or plugging in the halogen bulb to see if it lights up (if it does, the fuse is okay). Replace with a 15 amp fuse if needed.
• The polarity is incorrect. Make sure that the polarity setting is the same as the other side of the vehicle.
• There may be a malfunctioning part. To determine this, simply swap the ballast from the non-working side to the working side to see if the problem follows. Do the same for the bulb. Whichever part that the problem follows is the culprit.
• If even after swapping parts the problem persists on the same side, there is a voltage problem with the vehicle. Hook up a relay to bypass this problem.
Sorry to hear about the one bulb not performing as expected. In cases like this I can simply replace the component that is not working correctly with a brand new part. All we need to do is identify what part needs to be replaced using a simply test called the "SWAP TEST"
Basically, by using a process of logical deduction we can determine what component is causing the issue.
Start by swapping the bulbs to the opposite sides
If the issue moves then the HID bulbs need to be replaced
If the issue stays on the same side, proceed to swap the main ballast
If the issue moves then the ballast needs to be replaced
if the issue remains on the same side, then proceed to swap the ballast to vehicle connection
If the issue remains on the same side, the ballast to vehicle connection needs to be replaced.