2004 Outback, low beam is out on the driver's side only, low beam is bright on passenger side. Hi beams work normally on both sides. Ruled out the bulb. I'm not very good at troubleshooting electrics, but I want to try before I pay someone (since usually that doesn't work out much better than my own attempts anyway, but costs a lot more). I pulled the assembly where the socket is, figuring that the problem is likely there and not in the controls, relay or fuse. I did a continuity check of the wires in that assembly, and they all seem ok (but like I said, I'm not good at it!). Nothing looks overtly corroded or broken. My next step will probably be to go get the same assembly from a junkyard and put that in, to see if that fixes it. 

 

Here is a pic of the assembly I'm talking about.

 

 

In the meantime I am wondering what the wires in this assembly are for, if anyone knows: there is a green one that goes to the socket, a black one that splits and goes to the socket and somewhere, and a red one that goes somewhere ("somewhere" in this case being a connector that stayed on the car).  

 

Also, if anyone just knows how to fix this that would be good too! Or if there's a part number for this assembly, in case I can't find one. It says "20653" on the front of the cover, but that doesn't correspond to a part number as far as I can tell... 

 

Thanks!

You replaced the bulb and still no low beam?

Yes, the bulb is ruled out as the issue. It's something else.

Ruled out how? I've seen plenty of cases where people have simply looked at the bulb and that the filament is still "there", yet a new bulb is what fixed the problem.

 

Bulbs on these have a common power, and each filament is grounded through the dimmer switch inside the car. When you have an issue that affects only one filament the problem is going to be limited to the bulb or connector for that lamp. A wiring issue is possible but it will usually be confined to the area of the lamp or any wiring within the housing (such as what you have pictured above).

 

To rule out a wiring issue between the lamp and the dimmer switch you just need to identify which wire is the low beam ground and make sure it shows continuity to ground when the dimmer is in the low beam position.

 

What part of that housing needs to be "fixed"? Is it just that you don't know where the wires are supposed to to inside the lamp housing?

Edited March 2, 201511 yr by Fairtax4me

+1 on double-checking the bulbs.

Have you tried switching the two bulbs from left to right?

 

If the problem persists unchanged, then it's not the bulb.

If, however, the bad low-beam switches to the other side, then it's the bulb.

Check the bulb with a meter, even if it looks ok.  New bulbs can be bad too.  That said,  the lamp harness you have pictured is a fairly common failure, usually the bulb connector gets burned/melted.

did you check the fuse? most cars have separate fuses for each bulb so if one blows the other will remain on and not leave you without headlights at all. on my friends outback he had to replace the headlight housing due to a small crash and when we installed the new one the high beam was out on the drivers side it turned out to be a blown fuse in the fuse box located in the engine compartment.

Edited March 3, 201511 yr by sirtokesalot