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Low beam headlights on Buick LaCrosse

I have a 2006 Buick LaCrosse. The low beam headlights have stopped working. I thought that maybe the bulbs needed changed (since I usually have to change them every 6 months) but after changing one with a brand new bulb, it still doesn’t work. The “old” bulb looks ok. The fuses are also good (I checked them with a multimeter.) The only thing that I see in my shop manual is something about the ambient light sensor. If this has gone bad, would that cause the low beams to not work? The high beams work fine. The low beams will not work with the headlight switch in the “auto” or “on” position. I don’t see any DRL relay or fuse in this car. Thanks!

I am not familiar with your car but 6 month bulb life is a clue that there may be a wiring problem causing a higher currents or hot spots. Check all sockets and connectors for solid connections. Look for signs of hot spots or corrosion. Discoloration on the insulation or connectors etc.

I know some VW’s have had issues with poor headlight bulb life and it usually comes down to degraded connections causing hot spots.

Thank you. Yes I thought maybe some of the connections were bad, but I have been told that since my vehicle has Daytime Running lights that utilize the low beams, it drastically shortens the life of the bulb, especially when the brighter bulbs only have a life of 125 hours on average. So because they run all the time when the car is in gear, even in the daytime, the bulbs don’t last as long.

I’m Not Sure On An 06, But On Many/Most GM Cars This Could Be An Indication That The Multifunction Switch (T-signal/Headlight Beam/Wiper) Has Gone Belly-Up.

Try swapping the headlight relay with another relay (elsewhere in box) of the identical part number.

How many miles on the car?

“…my vehicle has Daytime Running lights that utilize the low beams, it drastically shortens the life of the bulb, especially when the brighter bulbs only have a life of 125 hours on average. So because they run all the time when the car is in gear, even in the daytime, the bulbs don’t last as long.”

Not true! I have 4 GM cars with DRLs (have had many years). I seldom ever replace a headlight bulb. The DRLs run at reduced power, not full current. This makes them last.

The car only has 77000 miles on it. There is only on relay in the relay box and that is for the high beams. I have checked the relay box in the engine compartment and the fuse block inside the car. Unless it is somewhere else. And this is the 2nd GM vehicle that I have had to change bulbs in after 6-12 months. And the other vehicle was a newer model. According to Sylvania (where many bulbs are made) and after I spoke with them about the bulb issue, they were the ones that told me that most of the bulbs have 125 hours or so of life. Which coincides with how much I drive at night and during the day. I will research where the low bean headlight relay might be.

Have You Tried Holding The Dimmer Lever In The Position That Would Momentarily (Ordinarily) Light Low Beams?
Try Holding It There (with automatic lights set to night mode, not DRL) And Have Somebody In Front Of Car See If They Stay On.
What happens?

I would suspect the light switch for the LOW beam position may be the cause. I don’t know what else is involved with your light system so there could be something else involved like the module. I would assume that when the lights are turned on manually the module would be bypassed. If you have the wiring diagram I suggest you check for power after the fuse for the lights.

Lights from Sylvania are notorious for short bulb life. Check out Phillips lights for longer bulb life. I had my van for over ten years before the first headlight failed on it.

There Are Two Types Of Dimmer Controls On GM Cars.

One type has a column mounted lever that you push and it flops forward for high beams and you pull it and it flops back for low beams.

The other type has a column mounted lever that pulls toward you and goes “tink” to turn on the high beams. Pull it again and it goes “tink” and turns on low beams. You always pull, never push, and it goes “tink” to toggle between high and low beams.

On the GM levers that fail that I’m familiar with, it’s the second type described that go “tink” and are always pulled. If the low beams quit AND the lever stops going “tink,” then it’s bad. I have diagnosed and replaced/repaired such a switch and it’s low beam outage.

GM has issued a recall for your vehicle for faulty low beam modules.

You should be getting a notification in the mail at any time.



Good one!
That recall is just in time (almost) for @stormchaser88 !

“headlamp driver modules”

Module=computer? Sounds like they hired a graduate from the Rube Goldburg School of Engineering with a Bovine Scatology degree in Difficulty Enhancement (BSDE)

@stormchaser88, you can make s urge your car is covered by the recall here:

Input your VIN and any open recalls will be displayed next. You can take a picture of your VIN at the base of your dashboard on the driver’s side, or your auto insurance card may have it. Mine does.

I seem to recall another poster here having this same problem recently. Suggest you search the forum for that thread. For the 6 month problem, if you purchase your bulbs at the same vendor, try another place. Sometimes a vendor will get a shipment of bulbs, all of which have a short life span. I had this happen w/my Corolla dome light, would burn out after 6 months to a year, several replacements from the dealership parts stock. Finally I decided to buy the bulb from a retail auto parts store, and it lasted for 20 years. In fact it just burned out yesterday by coincidence.

Thanks everyone. Yes I did find out from the dealer that GM was doing (or getting ready to do) a recall on a what is called the HDM relay (Headlight Delay Module) Unfortunately, I had to buy one so that I would have headlights to drive to work the next day. The relay was only $28 so that was the good news and it took 2 minutes to replace. AutoZone was where I got it and now they work again. But thanks again for all of the feedback.

Save the receipt. You can likely get reimbursed by GM for the part. File this away: if you are forced to do a repair before the warranty work can be done, GM will reimburse you. In this case, if you had paid the Buick dealer to replace the relay, you would have been reimbursed for parts and labor. If something like this occurs again, make sure to ask the dealer about that clause. No sense in worrying about it now, though.

Keith, do you believe the term “module” is confined to a specific part or technology? Really?
The guys that piloted the Lunar Landing Module might find that amusing. :lol:

Maybe it is similar to the difference between an ordinary mechanical relay and a solid state relay. They do the same thing, just using different methods.