Intermittant HID fault

**Big Dave** · 28th December 2011, 16:05

My ever so reliable HIDs that I bought from hids4us 28 months ago have started to play up. Sods law they're 4 months out of warranty.

Approx a couple of months ago I would get an intermittant failure of either headlight. Sometimes it would be weeks before one would play up again, sometimes every day. Sometimes the left, sometimes the right. Fortunately not both at the same time. A quick switch off and on of the headlights got them working again though.

However last night the offside one went off and stayed off. I did notice though that when I switched the headlights on, the faulty HID briefly but faintly flashed as it tried to strike up. The ballasts have a blue LED on them which remains illuminated when either HID bulb goes off. It's probably just a power in indicator, rather than power out.

I swapped the bulbs round this morning and can confirm the offside HID bulb was faulty. The quartz glass is also discoloured - which would explain why the offside light looked duller in appearance and not crisp white when compared to the nearside one recently.

My question is, would a HID bulb that's about to fail cause the light to go off at random intervals, or is there also a fault with the ballast(s)

Headlights look odd at the moment as I've got one HID bulb in one side and a halogen bulb in the other - lol. Presumably it's not illegal to have odd coloured bulbs in the headlights?

Have ordered a pair of new HIDs from ebay for £10.49, inc p&p. hids4us wanted more than double that. Hopefully the photo description on ebay isn't a library pic as they look exactly the same make as originally supplied.

**Big Dave** · 29th December 2011, 02:44

Originally Posted by Big Dave

My question is, would a HID bulb that's about to fail cause the light to go off at random intervals, or is there also a fault with the ballast(s).

Anyone?

Or is everyone ignoring my post because it's yet another HID thread? Perhaps I should have called it a different title.

**DAVIDD88** · 29th December 2011, 06:07

Change the bulbs in pairs and it will be sorted bud sounds like a dodgy or end of life bulb

**Big Dave** · 29th December 2011, 12:56

New bulbs are on order. Once fitted I Will report back as to whether I still get the intermittant problem of the lights occasionally going off.

**Big Dave** · 30th December 2011, 22:44

New HID bulbs arrived in the post this morning and fitted shortly afterwards. Same HID bulbs as originally supplied with my HID kit - Xenon super vision H7 6000K

Result!!

2 working headlights again and both the same colour.

Looking closely at the failed HID bulb, the wire that runs up the outside of the glass and enters at the top is loose. If you wiggle it you can see a break in the wire approx 3 mm inside the top of the glass. This is where the glass is mainly discoloured and cloudy. I suspect it's been arcing and reconnecting itself for quite a while which has been keeping the light working, but every now and again would separate again and cause the light to go off. Turning the lights off and back on again must have sent enough current down the wire to temporarily fuse it back together again.

Also the lights are nice and bright again. I thought it was weird the other day when a colleague parked his new Astra next to my Vectra and had brighter headlights than mine, and he's only got standard halogens. They must have been slowly deteriorating over a period of time, so that I didn't notice.

Time will tell as to whether the ballasts are also at fault, or if new HID bulbs have fixed the intermittant problem.