litronic testing?

Hi, just come back from a drive and noticed that the near side dipped beam lamp has failed on my 2001 beasty. A Simple bulb replacement I thought, so read the manual, removed the headlight unit and the litronic bulb. Tested the bulb in the drivers side unit and was suprised to find that it worked So, does anyone have any information on how to test the litronic unit or the wires coming to the unit or any other ideas on this? many thanks John

Assuming the wiring is ok (no short circuits or open circuits) - you may wish to chdck this assumption: the ballast may have died (or fused - not sure if they are user servieable components) Not sure how you test a dead ballast (excluding the "fit a working bulb" method, which you have in effect tried). OPC?

If you have swapped the lamps over you could then try swapping the ballasts, a multimeter is useful too for checking the supply voltage.

Also check the connector in the wing. They sometimes come loose in the bracket, so that the plug doesn't mate with the connector on the light unit properly.

sorry to sound silly but which part is the ballast and where is it located?

Before you start messing about with ballast resistors etc. do check the plug that connects the headlight unit... These do suffer from poor connections sometimes. I had exactly the same thing on my C4 and it was just a case of cleaning up the contacts. Do the indicators / sidelights / fog lamps all work in that light unit? If any of them are not working either, I would suspect connector problems.

Item 12:

thanks for all the suggestions. I've just spent a couple of hours stripping the lights and swapping various litronic parts between the sides to find the faulty item. It turns out that the silver electronics box on the back of the assembly is at fault (item 12 on the previous diagram). Bet that's not cheap from an OPC. Looks like I'll be on the phone to my trusty breakers tomorrow morning (yet again!)

Sitting down? Part Number 993.631.193.02. List price £488.92 inc VAT. Try the breakers, although I doubt they would want to take one off a working unit. Porsch-Apart or Douglas Valley, perhaps.

Not saying I like to cut corners or bodge stuff but I have converted the mount to fit one of these http://cgi.ebay.co.uk/HID-REPLACEME...arts_Vehicles_CarParts_SM?hash=item439b7f57fa Less than £10, 20 minutes work, good as new If you want to do this get the full ratings off the back, let me know what they are so I can link you to the correct one. MAHUSIVE saving. :thumb:

Ah, the "blown ballast" as they say in the Navy ... erm, anyway, that silver thing is the ballast (which acts as a current control for the HID bulbs). Nice to see OPC hasn't lost it's sense of humour. You could buy TWO complete litronic headlamps for just over £600 from a Bosch dealer. Even complete lamps from the OPC can't be far off the £977.84 it would cost for a pair of ballasts (I am sure Mr Hamilton will correct me). If you decide to pull it apart be careful any internal capacitors have discharged, or it could give out a shock. You will need to short circuit them with something metal and not your hand!

thanks for the suggestions, have just found someone selling a couple of used litronic headlamps due to an upgrade, hopefully one of those should do the job. This way at least I get a few additional spares for my rapidly growing collection!

Thanks to the wonders of Ebay I got a complete litronic equiped headlamp assembly for a decent price and am now fully operational again As an added bonus I had a nice long 5 hour round trip in the Porsche to collect it!