My driverside headlight, and only the headlight isnt working. Neither low or high beams but the rest of the headlight assembly works, i tried replacing the bulb, the ballast, and checked the fuses. The only thing i havent done is change the headlight switch relay. Anyone have any idea what the issue might be?

 

Have you tried checking for voltage at the plug? Try checking for voltage at the fuse box too and relay. Could help point you in the right direction of if its a broken wire and a fault in a control module

 

checked everything, i wasnt receiving a 12v signal from the wire that delivers the power to the mainheadlight, how would i go about fixing that?

 

If you have not already, download the EXL (Exterior Lighting) section of the factory service manual for you specific car from here. For certain years you will also need sections PCS (POWER CONTROL SYSTEM) and PG (POWER & GROUND)​​​​​​. It would be wise to download the whole manual, but...

From there, you mentioned you did NOT have 12V+ at the wire going to the HID ballast, did you also check the GROUND connection for continuity?

Each HID ballast (or controller) gets power from its own dedicated fuse located in the IPDM/er (big fuse box to left of battery). Did you check those fuses? On 2011 Coupe's, fuse #56 (15amp) is for (L) HID lamp- verify for your car.

If fuses are good, and you are still not getting 12V+, at the ballast, then you will have to trace that individual wire from headlamp to IPDM/er for any kinks, breaks, physical damage, etc.

Start with fuses. Never hurts to double check and PHYSICALLY test the fuses (the eyeball test does not count). It is likely NOT the relay or switch as the right headlamp works fine, correct?

 

sounds odd, but try and unplug the headlight just a little bit. doing that paired with some electrical tape fixed my issue with my headlight

 

I'm having the same issue. My driver's side headlight works sporadically. I have replaced the bulb and ballast. Sometimes it works and sometimes it doesn't?