Headlight intermittent fault

[Chajoma]

Every so often I have noticed at least one of my dipped headlights flickering while driving - it's difficult to tell whether it is one of both. It might happen for a minute or so and then stop. Last night while driving home, both dipped headlights stopped working. This morning I went to investigate and they were working fine.

 

I fear this is one of those problems that will be almost impossible to investigate and wondered if anyone on here has had a similar issue and found a solution.

[Picasso]

hello sounds like your head light ballast is failing my advice is to change both head light bulbs first this will be the cheaper option as the ballasts are at least £400 + vat from toyota if its the ballast i can give you a link to new aftermarket ones about £110 all in with the vat if you want to pm me your reg no. i will message you with a picture of location of the ballast 

[Ally]

Could be the battery, go get a free battery health check or buy a tester. Could also be bulbs, loose wiring or the ballast as mentioned above.

Edited August 1 by Ally

[Chris.ac]

On 8/1/2024 at 9:30 AM, Chajoma said:

Every so often I have noticed at least one of my dipped headlights flickering while driving - it's difficult to tell whether it is one of both. It might happen for a minute or so and then stop. Last night while driving home, both dipped headlights stopped working. This morning I went to investigate and they were working fine.

 

I fear this is one of those problems that will be almost impossible to investigate and wondered if anyone on here has had a similar issue and found a solution.

The bulbs have a lifespan.

The vapourised metal in the bulb eventually leaves a residue that causes an imbalance in current draw and heat dissipation. 

 

The ballast detects the current fluctuation and will start to flicker the lights, eventually they will fail to light up at all. 

 

Buy a pair of new bulbs.

 

Be sure wear gloves, and don't be tempted to flick the lights on to test, as you should leave them on for at least 30 minutes the first time after fitting.

[Chajoma]

Thanks for the advice everyone and sorry for the slow response.

 

I'm not sure what the ballast is. However, a bit of investigation and some googling suggested that it is the headlamp relay that is failing. This makes sense since both lights failed at the same time.

 

I'll keep you updated. 😉