Headlight strength mismatch - Car Test Fail

keithclancy

Just did my Annual test and a service at the same time, it came back as a fail on the headlights, apparently one is less strong than the other one and they said I'd need to switch out the whole unit for new ones as replacing one would also just cause an imbalance.

Also he said he changed the headlight bulb and tested it again and it didn't make it any better.

He was using a metal box that he shined the light into with a gauge on it, apparently the alignment was fine but it was just less strong ?

Also I noticed now the side light is out on one of the lamps .. would this make a difference ?

He just said I needed to replace both units altogether!

Any advice on what to do before I go off replacing both headlight units ?

I've never heard of this problem before

Eric Cartman

if those bulbs are HID's then one of them could be old. If its halogens and you've changed them id say its a bad earth and an auto electrician might be your best bet.

keithclancy

So I dismantled the lights and it turns out the lenses were manky, gave those a good clean and its much better now.

The Reflectors don't look great but they look about the same, so going to get it re-tested and hope for the best.

Also there's two different bulb types so going to replace them with the same type and hope that sorts it.

Cheers