I just purchased a 2003 3.2 TL. Initially I thought I needed to replace the driver side hid low beam bulb. After testing the bulb on the passenger side I have ruled that out as the problem. I used a wire tester on the igniter wire and it appeared to be live; now i'm wondering if its the actual socket thats the problem or is it the ballast? Can someone please advise me before I buy another part I don't need.

 

Which wire did you check? The wire from the car to the ballast, or from the ballast to the bulb?

Im going to assume you checked both. Check the fuses. If the fuses are good and plug from car to ballast are good. The ballast or the ignitor..(wire from ballast to bulb)..is bad.

You can go oem replacement if you want. Most have gone with an aftermarket kit for a fraction of the cost of replacing.

 

If it's not a bad bulb, then check for evidence of moisture or corrosion.
Make sure all the electrical circuit components are functional to that side.

 

After switching the bulbs back and forth and seeing that the bulb was fine; I checked the igniter wire. The wire appeared to have power, so I was thinking it may be a problem with the socket that the bulb goes in. There was no evidence of moisture or corrosion.

 

The socket that holds the bulb in the headlight housing is just to hold the bulb, it has nothing to do with the electrical connection, that is all done at igniter socket. Just make sure you align the keyway on the bulb base with the key in the headlight housing.

You need to cross-check components. As a double check, did you take the working passenger side bulb and try it in the driver's side to see if the problem appeared with a known good bulb?

 

This happened to me before I got my aftermarket kit. The bulb was fine (I tested it on the known working side) and it lit right up. I ended up switching the ballast and igniter cable to the side that worked and finding that it was the igniter itself, not the bulb or ballast. If you say the igniter has power, maybe just try it with the ballast that you know works on the other side

It is really just a process of elimination