Both Headlight Bulbs Blown Together, Is This Normal

[notbestpleased]

whilst driving home from work last night left a lit part of my journey and realised how poor the road was lit up, pulled over to check and found both headlight bulbs had blown, as there is only a single bulb now made the rest of my journey down country lanes very interesting, surely this failure cannot be safe, no warning? only running lights as back up?

[FROSTYBALLS]

Are you sure both had blown at the same time?

Other members have had the same occur.

It is possible that both may have been damaged by, for example, the impact of going over a deep pothole or similar.

No car has a back up for headlight bulbs blowing.

[Konrad C]

I thought all cars had side lights/DRL, dipped beam, and main beam headlights.

Now when I go into unlit country roads, I switch on the main beam by pushing the light/indicator stalk forward. Now hopefully everyone knows this but you never know!

The original poster does not say in detail which head light, main or dipped beam are not working properly. He states that only the DRL are working!

Now if the bulbs have blown at the same time, it can happen. There are more things i could say in response to your post, but every car has the same light system. We the owners should check all lights to make sure they are working, and carry spares. The only problem is how difficult the change the bulbs on some cars due to access.

Hopefully you have had the lights fixed and any other checks done.

[TomdeGuerre]

Daylight Running Lamps (DRL's) are not meant for a back up should headlight filaments fail, even when my sidelights are turned on the DRL's dim noticeably - as they're supposed to. If you turn all the lights out so you can drive on the DRL's then you'll have no rear lights showing, although you could get over that pro temp by keeping your foot resting lightly on the brake pedal. Probably much to the annoyance of other drivers coming up behind you but safer than them running into you. Or maybe use the 4 way flashers.

Wouldn't the fog lights be a back up? Don't know for sure but as long as the headlight switch is in the ON position, regardless of whether the filaments were blown or not, surely the fog lights would come on, leaving the normal rear lights working.

[Konrad C]

Daylight Running Lamps (DRL's) are not meant for a back up should headlight filaments fail, even when my sidelights are turned on the DRL's dim noticeably - as they're supposed to. If you turn all the lights out so you can drive on the DRL's then you'll have no rear lights showing, although you could get over that pro temp by keeping your foot resting lightly on the brake pedal. Probably much to the annoyance of other drivers coming up behind you but safer than them running into you. Or maybe use the 4 way flashers.

Wouldn't the fog lights be a back up? Don't know for sure but as long as the headlight switch is in the ON position, regardless of whether the filaments were blown or not, surely the fog lights would come on, leaving the normal rear lights working.

Tom if the poster drove with his foot lightly on the pedal, it might not have enough play so the brake pads could touch the discs, causing friction. Any way I think you said that tongue in cheek.

The original poster does not seem to have much technical knowledge of cars, from what he stated in his post! Mike (Frostyballs) clearly said that no cars have a back up light system.

The owner has minimum of 3 levels of lights (side, dipped & main), the optional DRLs and fog lights if fitted. So unless there is a total electrical failure, these will be your "back up".

DRLs to me have been a source of a new problem, as some owners do not realise to use normal night lights. I have seen cars with no rear lights on and just the front DRLs on, and even with auto lights function switched off!

So long as the lights work and the owner knows the function, there should be no issues.

Carrying spare bulbs is one thing, changing is another.

[FROSTYBALLS]

As far as I'm aware the HIR2 bulbs which are fitted to the current Auris are single filament. Main beam is produced by an actuator routing the light output through a lens. So if a bulb blows, one loses dipped and main beam.

As I said no car has a back up (ie a secondary system that comes into play in case of failure) for the headlight bulbs, and on some cars one can use alternatives such as front foglights - but that depends whether front foglights are fitted.

On the first generation Auris, one has H11 bulbs for dipped beam and HB3 bulbs for main beam - so one doesn't have the same issue if one set of bulbs fail.

On Toyota's, HIR2 bulbs have now become standard fit for the Aygo, IQ, Yaris and Auris that I know of.

[Parts-King]

These days people think that owners responsibilities like checking lights and levels are a thing of the past, I had a chap in the other day who got quite umpty because a bulb had gone and they should not "go" between services as how would he know it had gone???? weird!!

I reckon one bulb might have blown previously without knowing, then when another one blew, the OP noticed. It would not be the first time that has happened