One Low-Beam Out

[volnix]

Hi,

My driver-side low-beam on my 2007 Yaris sedan went out this past Friday so I replaced the bulb over the weekend. Still no low-beam. I've checked the fuses for both bulbs and the main HLP fuse. I pulled the bulb out and verified that the coil is still intact (it's intact on my old bulb as well), so I'm inclined to think it's something else.

To add to the weirdness, I stuck the passenger-side fuse in the driver-side location to make SURE the fuse was good and got just a tiny little light, but certainly not the full illumination. This tells me the wiring is fine too.

I went ahead and replaced the fuse since I had some spares to no avail.

Also, both high-beams are fully functional still.

Anyone have any advice on what to check next? I'd love to fix this myself instead of taking it to the shop for a headlight out (just feels wrong lol).

Thanks!!

[Betrivent]

I'd get two new fuses and replace both existing ones just to eliminate them out of the equation.

[volnix]

Hey, sorry, I don't think my original post made sense about that. I already tried that since I had some spares laying around. Thanks for the help though!

[ilikerice]

Have you tried to swap the passenger bulb (known good bulb) and the drivers bulb (possible bad bulb) to see what results you get. While the bulbs are out. I would get a volt meter and check the voltage coming from both sockets and compare.

[CoryM]

Interesting. Unless your connector is melted (common with brighter aftermarket bulbs), I'd guess your "running light relay assembly" (aka DRL module) is kaput. Honda and Nissan et al are famous for this, but I haven't heard of a Yaris yet. I would suggest removing the module, pulling the cover off it and looking for a poor solder connection. Very common for other cars, and usually you can just re-solder it and are good to go.

Cheers.

[volnix]

Interesting. Unless your connector is melted (common with brighter aftermarket bulbs), I'd guess your "running light relay assembly" (aka DRL module) is kaput. Honda and Nissan et al are famous for this, but I haven't heard of a Yaris yet. I would suggest removing the module, pulling the cover off it and looking for a poor solder connection. Very common for other cars, and usually you can just re-solder it and are good to go.

Cheers.

That was what I thought at first, but after a little more research determined it doesn't actually have a headlight relay. They're just straight-up headlights driven by the switch on the steering wheel stalk (not DRL or anything). Guess that's what you get when you have the basest base model they offer (it's a stick shift, manual windows, manual locks, etc.)

[volnix]

Have you tried to swap the passenger bulb (known good bulb) and the drivers bulb (possible bad bulb) to see what results you get. While the bulbs are out. I would get a volt meter and check the voltage coming from both sockets and compare.

I'm kind of surprised I didn't think to try this. That would at least give me a definitive answer to whether it's the bulb in any way. What voltage would I expect to see if things were functioning as expected? I'm pretty handy with most areas of car maintenance, but electrical is not one of them.

[CTScott]

If yours definitely does not have the H-LP relay, then try bypassing the headlight stalk (which is likely the culprit).

To bypass it for the low beams, on the headlight stalk connector jump the blue wire next to the pink to the large white/black wire.

[ex-x-fire]

Get a test light & check for power & ground at the bulb connector. Test the fuses for voltage on both sides.

[volnix]

If yours definitely does not have the H-LP relay, then try bypassing the headlight stalk (which is likely the culprit).

To bypass it for the low beams, on the headlight stalk connector jump the blue wire next to the pink to the large white/black wire.

From doing some more research yesterday, I'm thinking you're probably right. I'm out of town on business until tomorrow, but will try swapping bulbs and try bypassing the stalk tomorrow afternoon.

Thanks for everyone's help!

[volnix]

FYI, I ended up getting bogged down with work and just couldn't find time to look at it so I took it to the shop instead. Embarrassingly, they said it was a bad bulb. Still don't understand how I managed to get a bad bulb from the shop, but oh well. Thanks for your help nonetheless