Epos

MY01 STi V7

One of my HID headlamps is not working, it seems to be a loose connection, as the light has comes on occasionally.

I have checked the headlamp cradle holder and there is nothing unusual.

Does anyone have any ideas where I should look for a possible loose connection for this HID lamp?

Nathan L

Have you tried cleaning all the earthing contacts?

HID takes 22-23000 volts to ignite the gas. If the contacts are dirty it can be difficult to get them to both fire together.

Nathan..

Epos

I just cleaned them, but unfortunately made no difference

Apple

Are they the OE HIDs or aftermarket, i.e. they are standard on the car or have you fitted someone's HID kit (e.g. Autolamps or others)?

This is the OE setup:



If they are aftermarket, have you got a dodgy connection from the loom to the power relay and also from the relay to the ballast? If they are intermittent, is there a wire with a break in it that touches occasionally? You could use a multimeter to do continuity tests on these wires.

As Nathan mentioned, the ballasts spark up at 20+KV so I wouldn't go poking around them with a pointy wire . AFAIK the ballasts can fail over time but this would possibly mean you don't get any light rather than intermittently.

Andy

Epos

They are the lights as show (standard)

What are the ballasts?

Nathan L

The ballast units are the metal grey boxes shown above.

These are the units that convert 12v DC to 22000v

I would advise caution when checking these, as the boxes can hold a residual charge. Always disconnect the battery when working on HID, IMHO.

Nathan..

Epos

So i guessing if there is a problem with the HID unit it is going to be the headlight or that box. Not many other places it could be.

I will look 2morrow, where abouts is the ballast located, just beneath the headlight unit?

Apple

Dunno where the ballasts are on an official Subaru setup - it's probably easiest just to follow the orange sheathed wire back until you get to it...

It's best to get professional / qualified help to check the ballasts, mainly for safety and also for knowing how they are supposed to work / how they can be checked for the correct operation.

I'd guess it's better just looking for bad connections and bad earths in the system and see if you can find anything like that first...

If you have a look at the bulb

a) don't touch the glass as the acid in your fiingers will start eating into / degrading the surface of the glass, it can fail sooner, and
b) the bulbs are like fluorescent tubes, i.e. no filament so don't think it's blown and chuck it away . they also have an off-white powder stuck to the inside of the capsule (yet again, it's not the insides that's burnt away and failed...)

Andy