GM headlight died. Again.

 Daughter stopped by and showed me that, once again, one of the headlights are out on her Traverse. This will be the 5th time since she's had the 2015 Traverse (64K miles). The thing is, I see GM trucks and SUVs with one light out (headlight, DRLs, etc) ALL THE TIME. Even my wife will see something coming at us with a light out and now asks "GM?" 

 What's the story on this issue? I can't imagine GM buys different bulbs then the rest of the industry. Is it a wiring issue? Cheap relays? My 2002 Ranger still has the original bulbs and that truck has almost 180K on it.

Sorry if this has been discussed previously, but it's been bugging me for years now. 

Rant/off

Are you following the recommended fluid change interval?

I see alot Hyundai and Kia vehicles with failed lightbulbs all the time, way more than other brands.  No idea why.

Replace in pairs. Something nobody does.

Faulty design. GM runs too many amps through their headlight harness and it burns out the bulbs fast.

Javelin said:

Faulty design. GM runs too many amps through their headlight harness and it burns out the bulbs fast.

You probably need to explain the math on that one.  Are you suggesting all the other manufacturers have resistors in the headlamp circuits?  The resistance of the bulb and the voltage in the charging system is what controls the amperage.

Wellllll....

If there is a lot of voltage drop, the bulbs will burn out faster.  Something about the way the filaments lose material to the gases in the bulb, and the material re-deposits on the filament as part of normal operation, and if the voltage is too low then the bulb runs too cool and the metal instead condenses on the inside of the glass, which is why dead bulbs look like used flash cubes.

Not a case of "too many amps" as much as "wiring not good enough".

See also: GM's horrible DRL scheme where they ran the high beams in series.  That ate bulbs.

Streetwiseguy said:

Javelin said:

Faulty design. GM runs too many amps through their headlight harness and it burns out the bulbs fast.

You probably need to explain the math on that one.  Are you suggesting all the other manufacturers have resistors in the headlamp circuits?  The resistance of the bulb and the voltage in the charging system is what controls the amperage.

Well my knowledge of electricity begins and ends at electrocuting myself, so I am probably wrong on the how, but the WHY is definitely design fault. When I was slinging car parts commercially GM DRL's outsold all other bulbs combined by a factor of 2, the most popular headlight bulbs were for GM's, and we stocked 10x the amount og GM connector ends for headlights than all other weatherpack/GM stuff.  Something about how they design the circuits melts the connectors and burns out bulbs constantly. Back in the fox-body era it was Ford that did that, but that was because they range full voltage/amperage through the headlight switch with no relay. A headlight relay wired in so the headlight switch didn't carry the load solved that. We never had a solution for the various GM maladies.

I have a long-standing suspicion that GM wiring harnesses are made in England by Lucas.

CJ said:

I have a long-standing suspicion that GM wiring harnesses are made in England by Lucas.

Ha. Oddly enough none of my MGs killed headlights this bad. Makes me wonder about the future electric cars from GM too...

stan said:

CJ said:

I have a long-standing suspicion that GM wiring harnesses are made in England by Lucas.

Ha. Oddly enough none of my MGs killed headlights this bad. Makes me wonder about the future electric cars from GM too...

But have your MG wipers ever been possessed by demons?

Might be time for a led swap. My Subaru popped lightbulbs all the time. I swapped to LEDs and have been fine since with much better lighting. 

Pete. (l33t FS) said:
which is why dead bulbs look like used flash cubes.

 

Now there's a deep nostalgia dive. 

In reply to GTwannaB :

But then you have to try to avoid oncoming traffic veering into your lane because the drivers have to close their eyes until you're past them.

GM pickup trucks seem to have the same issue with tail lights not lasting long.  I always attributed it to bad grounds that have high resistance. With a poor ground the electricity effectively has more resistance in the circuit. Higher resistance means more amps needed to get the electricity to flow through a circuit. When this happens the bulb is now the weekday point in the circuit and acts like a fuse. 
 

I have always speculated that in the GM trucks that a ground someplace is attached to somthing that is painted or somthing like that.  No proof on my part just speculation.  
 

@the op. You could try running new grounds for your headlight circuit and see if that helps.  

In reply to dean1484 :

That's not how electricity works, increase circuit resistance but voltage on the circuit remains the same, the current will go down. Voltage pushes current, resistance resists current.

Floating Doc (Forum Supporter) said:

Are you following the recommended fluid change interval?

You're joking but my family hauler Pontiac Montana used to blow a headlight every winter like clockwork due to fluid building up inside the headlight, drilling some drain holes seems to have fixed it...

I agree that it must be a GM wiring issue.  There are only about 4 big suppliers of light bulbs out there, and every GM I've ever had used Sylvanias.  I don't think it's the bulb, especially because you can replace them with Hella or a Phillips and they blow out just the same.

Likely poor ground or inadequate wire gauge causing reduced voltage.  Test voltage between the pin in the connector and the frame with the lights on.  My guess is that it will be notably lower than at the battery.

GTwannaB said:

Might be time for a led swap. My Subaru popped lightbulbs all the time. I swapped to LEDs and have been fine since with much better lighting. 

Yeah... LEDs don't work well in factory buckets.  Focus is totally wrong.  I got some for my Fordzda Branger and after two times being pulled over for having my high beams on (which they weren't) and countless oncoming drivers flashing their highs, I switched back.

Curtis73 (Forum Supporter) said:

GTwannaB said:

Might be time for a led swap. My Subaru popped lightbulbs all the time. I swapped to LEDs and have been fine since with much better lighting. 

Yeah... LEDs don't work well in factory buckets.  Focus is totally wrong.  I got some for my Fordzda Branger and after two times being pulled over for having my high beams on (which they weren't) and countless oncoming drivers flashing their highs, I switched back.

 

I was told that the only problem with LED headlights is you have to do the high and low beams at the same time.  If you only do the low beams, the high beams are worthless because they will be dimmer than the low beams.

It is completely lost on these people that it is kind of a major D move to effectively be driving around with your high beams on all the time.  I brought it up to him and his response was "well, I want brighter headlights"

Our 06 Sierra is still running all the original bulbs. Purchased new. 

Pete. (l33t FS) said:

Curtis73 (Forum Supporter) said:

GTwannaB said:

Might be time for a led swap. My Subaru popped lightbulbs all the time. I swapped to LEDs and have been fine since with much better lighting. 

Yeah... LEDs don't work well in factory buckets.  Focus is totally wrong.  I got some for my Fordzda Branger and after two times being pulled over for having my high beams on (which they weren't) and countless oncoming drivers flashing their highs, I switched back.

 

I was told that the only problem with LED headlights is you have to do the high and low beams at the same time.  If you only do the low beams, the high beams are worthless because they will be dimmer than the low beams.

It is completely lost on these people that it is kind of a major D move to effectively be driving around with your high beams on all the time.  I brought it up to him and his response was "well, I want brighter headlights"

This is not true. The high beams are a different color, but they are aimed differently and not focused. I run LED in the projector's and standard H1's for the high beams in both rios. 

The DRLs, or other lights being used as DRLs, also have way more runtime than basically any other bulb on the vehicle. I always assumed that's what killed them.

dean1484 said:

GM pickup trucks seem to have the same issue with tail lights not lasting long.  I always attributed it to bad grounds that have high resistance. With a poor ground the electricity effectively has more resistance in the circuit. Higher resistance means more amps needed to get the electricity to flow through a circuit. When this happens the bulb is now the weekday point in the circuit and acts like a fuse. 
 

I have always speculated that in the GM trucks that a ground someplace is attached to somthing that is painted or somthing like that.  No proof on my part just speculation.  
 

@the op. You could try running new grounds for your headlight circuit and see if that helps.  

My Chevy taillights gave up the ghost just past the warranty. I went on EBay and bought a set for something like 12 cents and a pack of cigarettes.  That were still working perfectly 18!years and 250,000 miles later. 

Vibration (or lack of isolation from same) kills anything with a filament that operates hot enough to glow white.

And it's the bulb that determines how much current flows through the circuit for a given supply voltage.