Headlamp and ballast

[jonthetourist]

I suspect this topic has been covered, but I can't find it - sorry.

My driver's side dipped headlight is intermittently not working. So not as simple as just a bulb replacement. I have read about ballast, but don't really understand it. I also looked up the bulb at Halfords and noticed they won't fit it. My feeling is probably replacing bulb and ballast both sides is the right way to go, but how big a job is that likely to be, and is there any danger in it?

Thoughts appreciated.

Jon

[Las Palmas]

If the car has Xenon lamps replace both lamps and ballasts. 

Lamps first. Then ballasts and connect to lamps before adding 12V to the ballasts.

If car has Halogen lamps no ballasts.

Remember not to touch glass on lamps.

[Beamish]

 

I had the same problem with a 2006 IS250 fitted with Xenon lights and new bulbs sorted it. 

You could try swapping the lefthand and righthand bulbs around and see if the problem moves which would confirm that the problem is the bulb.

In any event it would be best practice to replace the bulbs in pairs as the colour and light output diminishes as the bulbs age.

Dec.

[Herbie]

Intermittent working is often the bulb itself (or lamp, as we electricians call them - bulbs grow, lamps glow) and as John says, if HIDs then replace both at the same time.

High Intensity Discharge (HID) lamps light up using a plasma arc rather than a filament, which is why a ballast is required. It takes about 20-25,000V to strike the arc and about 80V to maintain it, so switch the lights off and wait about 10 minutes for any residual charge to drain away before handling them.

[cruisermark]

I had the ballast go on my previous 430 - it was a bumper off job for the garage. The balast is attatched to the underside of the headlamp.

[jonthetourist]

Thanks folks. How big a job is replacing the lamps? (not bulbs!)

Jon

[Cotswold Pete]

On 2/11/2023 at 11:56 AM, Beamish said:

 

I had the same problem with a 2006 IS250 fitted with Xenon lights and new bulbs sorted it. 

You could try swapping the lefthand and righthand bulbs around and see if the problem moves which would confirm that the problem is the bulb.

In any event it would be best practice to replace the bulbs in pairs as the colour and light output diminishes as the bulbs age.

Dec.

This would be my route to suss out issue.

I had similar problem with my 400, with dipped being flaky.  Two new bulbs perked up the night driving

One thing I noticed is that the dipped beam gets fainter but there seems to come a point when your eyes just find it too difficult to see ahead, and what I observed before my most recent bulb replacement was this.  'If you fog lights make a huge difference to the light on the road it sure is time to replace the bulbs'.