Replaced headlight, driver's low beam still does not work.

[Xist]

Bringing in the old part should have been obvious.

There was a post on Jalopnik seven years ago about a guy that was put on hold by Autozone, someone else picked up, asked if he had been helped, and then put him on hold again. He finally got tired of it, drove over, and found four employees and two customers. He demanded to know why he had been on hold for forty-five minutes and asked to speak to the manager. There were endless stories of people dealing with idiot parts store monkeys, including ones where they already had the part number, but the monkeys insisted on knowing what make, model, year, engine, and trim.
Then there were people making excuses for the monkeys, criticizing the customers, etc.

[Frank Lee]

I regret not suggesting simply swapping out the bulbs left for right early on as a means of seeing if it was a bulb problem or something else. I didn't post because it looked like there were plenty of suggestions pouring in.

[redpoint5]

Originally Posted by Xist

Bringing in the old part should have been obvious.

There was a post on Jalopnik seven years ago about a guy that was put on hold by Autozone, someone else picked up, asked if he had been helped, and then put him on hold again...

I just had this experience with an online chat with India. My problem was with a WiFi connected power monitoring outlet that was reporting a power draw of 234,763 Watts. After explaining the problem and my troubleshooting steps, the guy said he was going on break and passed me off to someone else. I then spent 5 minutes explaining what the problem was and my troubleshooting steps and the woman said she was going on break and passed me off to another guy. The 3rd guy simply said to upgrade the firmware, but the app said there were no firmware updates.

Finally the guy gave me a link to download firmware not available to the public, and I updated the device with zero instruction on his part. He would periodically ask if I was still there, and I would tell him I'm trying to figure out which of the 6 executables in the download to run, and which of the 30 files to select as the firmware.

Monkeys aside, I really liked the employees at Cost Less auto parts. Not only were the parts way cheaper than anywhere else, the employees were extremely knowledgeable.

[Fat Charlie]

Originally Posted by freebeard

You gotta be able to laugh at yourself, you can't always rely on others.

That's another place where ecomodders step up for each other!

Originally Posted by Xist

There were endless stories of people dealing with idiot parts store monkeys, including ones where they already had the part number, but the monkeys insisted on knowing what make, model, year, engine, and trim.
Then there were people making excuses for the monkeys, criticizing the customers, etc.

I'll cheerfully sell you anything. "Customer supplied part number" on the bottom of the slip makes everyone understand where the wrong turn happened, if one happens. If I get vehicle information to look it up myself, that goes on the slip, too, and for the same reason.

[me and my metro]

I use Napa Prolink at work and I have it on my phone. It is their online catelogue system and also checks inventory and our price.

[Fat Charlie]

Prolink is really good at cross referencing part numbers, too.

[Xist]

I swapped the left and right high beams. O'Reilly's and Autozone did not show a part number for the headlight relay, but Napa did, although it said to call to see if it was in stock. I did not have any idea how it could have been the problem, but swapping it out would have been easier than the diagnosing steps I found.

[cajunfj40]

One night out with the family at a movie we came out and found my wife's 2007 Mazda5 had no functioning headlights. Luckily there's a NAPA at the other end of the parking lot, so I pull in and go to buy a pair of bulbs. Guy finds it in his system, sells me the pair, I go out and start scratching the heck out of my hands trying to get the bad bulb out. Finally get the retaining bail off the back of the bulb, pull it out, and go to grab the new one to put back in. It doesn't match the old one. Take them both back in and ask the guy at the counter what gives? He takes a look at the old bulb, takes it from me, unplugs the factory adapter from the back, and hands me the two pieces. I apologize, and go back out to resume fighting with the retainer bails. Finally get the two new bulbs with adapters installed and one side is still out. Fight with it more, and figure out that if I wiggle the adapter, it works intermittently. Sigh. Drive home on one headlight. Call the local parts store near home the next day and the guy says "Yeah, we have that part under X brand. Must be "known bad" from Mazda, because X brand only picks up the problem parts that the OEM's don't do right." I order two, install one, it works. I toss the spare new one in my toolbox (along with the bulb that was good on that side with the bad adapter...) as a spare.

Other side is intermittent right now. Been below -10 for a few weeks so I haven't fixed it yet - and it always comes on if I give the headlight a physical thump. Not sure if busted filament or bad adapter yet, I'll check it when it finally quits or it gets a lot warmer out. Too cold to mess with that dang wire bail.

So, my troubleshooting for non-functioning headlight starts with "give headlight a physical thump." Beware adapters on the bulbs in Mazdas (and probably related Fords).

[redpoint5]

Originally Posted by cajunfj40

Other side is intermittent right now. Been below -10 for a few weeks so I haven't fixed it yet - and it always comes on if I give the headlight a physical thump. Not sure if busted filament or bad adapter yet, I'll check it when it finally quits or it gets a lot warmer out.

Almost certainly a poor connection between the harness connector and the bulb terminals. They are either loose and/or corroded.

[cajunfj40]

Hello redpoint5,

I've had a few headlights that could be limped along with the "thump" treatment for a while. Hard to tell whether I didn't have two faults: intermittent bad contact, and ultimately a failed filament when the thump no longer worked to fix it. Just the scraping action inherent in unplugging the failed bulb and putting in the new one will renew the contacts somewhat, so definitely a confounding variable there. I'm pretty sure I've "fixed" a bad bulb so it would light up one or a few more times - IE the two flailing loose ends of the filament welded themselves back together when I shook it while it had voltage hooked up. Never lasted long, of course. Could be a trick of the light and a bad connection, though, as you say. I think it's probably the adapter in this case, since this is still the OEM one on this side.