I have a headlight out in my '06 3 touring, and I swapped bulbs after a new set gave me the same problem, and the bulb that I thought would have been burnt out was good.
Is there some kind of relay or balast on this thing?
I have whatever headlights come on a touring, and yes it has a bulb.
Thanks

 

what bulb size is it? check the wiring and if you have a box bigger than the size of a plug then you have a ballast, I'm not too sure about stock hids on the mazda 3 as to where the ballasts are but if your bulb is good you have a wiring issue. second thing to try is switch out the fuse i know your thinking one light works so the fuse is good but I've seen lots of times where something didn't function right because of the lack of current going thru a some what burnt fuse.

 

It takes or fits the H7 bulbs, does that help? I haven't been under the hood in a while & don't recall about the box (which I think you mean would be right behind the bulb). I don't really see why it would be wiring if I haven't had any work done in that area, but I'll keep that in mind as a possibility. I'm thinking ballast or possibly the fuse idea you mentioned.

 

If you have the touring model then you should have regular halogen lamps and not the HIDs. Incidentally if you had HIDs in a '06 model then you would have the GT trim. You'd have heated leather seats, bose audio, and (if you have a hatchback) LED tail lights. In addition there would be a headlight leveling **** to the left of the steering wheel by the dash dimmer ****. Conversely if you have the GT trim you have HIDs.

Now with that out of the way and assuming you have halogen lamps. There is no ballast for the halogens. If you had HIDs then it's mounted to the bottom of the housing. Basically all you have is the lamp, the adapter on the back of the lamp, and the wiring plug. If all of those things appear fine then I'd check the voltage on the wiring with a multimeter to confirm that you're actually getting power to that light. If not then make sure to check all of the fuses/relays in both the PJB and engine bay fuse boxes.

Lastly to confirm the issue is just one side vs. another and to rule out other things try swapping the lamp from one side of the car to the other. That will help rule out the wiring to the affected side.

 

I don't have the GT, because my leather seats aren't heated, and I'm sure the whould have pointed that out when I bought it as a selling point. JBL optional audio with cd changer I believe, though I don't think the speakers were quality, because they blew pretty quickly. anyway (and I don't see JBL on anything) it's a sedan.
Do the H7's fit on HID vehicles?
I did swap the bubls, and the problem stayed on that one side with both bulbs working on the good side, I'll get to checking things with a meter when I get back in town. We're going to help clean up in Joplin Missouri after the tornado went through there, but I'll update this when we get back.

 

I have an 06 Touring that comes with stock H7 headlights.

 

So where exactly is LaHabra? In the US there's no JBL sound system and all leather seats are heated.

To answer your question H7's do not fit on HID vehicles. The lamps are a different size/shape and the bases are completely different. If you're using H7's then you definitely do not have HID headlamps which means there is no ballast. The problem's got to be in getting power to that lamp either due to a fuse/relay issue, or with the wiring itself.

 

there is a seperate ground for each light... could be one is broken. One is in front of the battery / engine fusebod, and the other I think is under the #3 engine mount near the passenger side strut mount.