Since I bought the car 18 months ago the drivers side dipped beam keeps failing. Bulb is ok. I am on the 2nd headlamp and 2nd ballast. Anyone any ideas before I throw more money in the parts bin

Had this recently on mine, turns out the headlights have water in them and where the ballast is located (directly under the headlight) means that it just drips directly into the ballast.

I recently changed my ballast a few weeks ago, and it failed within 2 days. I took the headlight back out and low and behold the ballast was full of water again! I allowed the headlight to fully dry and blasted it out with compressed air and a fan to get it all out. Dried the ballast too and unbelievably it came back to life after a few days and touch wood its been spot on since.

Do you have all the headlight cover caps on the back of the units? I think there are 3 per headlight on the pre-facelift.

On 17/06/2026 at 14:34, nigelw said:

Since I bought the car 18 months ago the drivers side dipped beam keeps failing. Bulb is ok. I am on the 2nd headlamp and 2nd ballast. Anyone any ideas before I throw more money in the parts bin

Thanks for the reply. One cap is missing off the back and moisture inside the lamp. So I would expect there is likely water in the ballast. I found a replacement lamp on Ebay and bought another new ballast. So 3rd time lucky.

@nigelw I think it would be wiser to fix the missing cap (and moisture) issue first....

It's such a stupidly bad design, and makes sense why the FL version has the ballast fixed to the plane 90° to the original so water doesn't trickle into it.

I'm not posting in this thread again because since posting...my other one has failed! But I did re-fit the covers last week to that one so i'm assuming water has struggled to get out and just gone into the ballast... great! Not sure how i'm going to sort this now without taking THAT side out as it's a bit of a PITA to get to.