Seeking Help With HID Diagnosis

[Fred Munro]

The bulb is just an arc-discharge capsule, so if it lights sometimes it should light all the time. The problem is more likely with the ballast or the igniter. If the bulb lights and then goes out later, it is likely the ballast. If the bulb fails to light when you turn on the lights, it could be the igniter. I don't know the Volvo system - some system have separate igniters, and some have them incorporated into the ballasts or into the capsule base. My Audi HIDs have separate igniters. I've not found a good way to troubleshooting HIDs other than by replacing parts to see what fixes the problem, and to this end I have a box of spares I bought cheaply off eBay over the years.
The first step, as you mentioned, is to check the power feed connections and grounds.

HTH

Fred Munro
'97 S6

-----Original Message-----
From: quattro-bounces at audifans.com [mailto:quattro-bounces at audifans.com] On Behalf Of gbowles at cansafe.com
Sent: October 3, 2011 10:01 PM
To: Quattro List
Subject: Seeking Help With HID Diagnosis

My Audi's all have halogen headlights. The help I'm looking for is for the wife's Volvo, so NAC here.

A while back the 2004 XC70 began showing the "bulb failure, low beam" error message on the dash. The driver side headlight was out. My immediate thought was, "Oh oh, it's a $150 bulb problem". Then the message disappeared and the bulb was working.

I haven't found any pattern to it, but every so often the bulb goes out and the message re-appears. Eventually it will come back on and resume normal operation. I have found that if I shut down and re-start when the error appears everything returns to normal, for  while. This is beginning to sound like Windoze, don't you think.

My experience with HID is zero so I hope someone here can shed so light on what is going on. Do I just replace the lamps and hope that's the problem? (With halogens that's what I'd do and it would cost me $25.) There are other (costly) components that could be the problem, so trial & error could get expensive. I haven't found much info on HID diagnosis other than "check the connections for corrosion" which is what I plan to do next.

Any advice is appreciated. TIA


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Mr. Greville H. Bowles
Ralston CanSafe
525 Glengarry Cres.
Fergus, Ontario N1M 2W8
Phone: (519) 787-1297 Ext. 39
Fax:  1-800-669-2392
E-mail:  gbowles at cansafe.com
www.cansafe.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


_______________________________________________
quattro mailing list
http://www.audifans.com/mailman/listinfo/quattro
http://www.audifans.com/kb/List_information