Passenger low beam bulb failure after HID trial

[nsfwaldo]

Yet another thread about a single headlight failure. I recently put in VIVA’s HID conversion kit just on the low beams and they took me a while to get figured out. I had to use a capacitor to make them not flicker but did eventually get them working. They’ve worked for about a month or so and the other day one just stopped working all together and gave me the bulb failure warning message. I got pulled over for having one light working so I decided to swap back to halogens. Now the same passenger headlight still doesn’t work and the little drl lights under the headlight also don’t work. I checked fuses and tried multiple bulbs to no avail. Anyone have any other suggestions on what may be wrong or what I can check?

[pbierre]

The fact that both the lowbeam halogen and courtesy light underneath it (on passenger side) are failing, that suggests a discontinuity in their common ground wire. Pull out the halogen bulb...one of the two harness contacts should have <0.3 ohms to ground.

[hoonk]

I decided to swap back to halogens.

Thanks for no longer blinding every driver coming towards you (with the aftermarket HID kit)


You don't say what year you have - If it's got H11 bulbs the connector melts at the bulb and the small 3? watt bulb next to the H11 commonly go out. An inexpensive volt/ohm meter would help you test voltage, ground and for an open circuit in a light bulb.

I've found the replacement aftermarket connector to be of poor quality and melt again, I would suggest using the expensive Volvo part if needed. 31299732

[nsfwaldo]

They weren’t too bad haha. I had em angled all the way down and could see a pretty good line where they cut off below people heads haha. But anyways, yes they were the h11. I have an 05 XC70. Forgot to mention that. The ground seems fine to me but I have not tested it with a voltmeter yet. No visible melting anywhere. But both courtesy bulbs on both sides are out and just the one low beam on passenger side. I’m beginning to believe it’s an CEM issue :/

[hoonk]

I’m beginning to believe it’s an CEM issue :/

Yes I have had several cars come in with a bad hlamp bulb, install new bulb, no work, check fuse, ok, check power, still no 12v. Next day (or later same day) bulb starts working. Maybe if a bulb shorts out (not just a broken filament) the cem trips an internal "circuit breaker".

And have replaced CEM's for strange bulb not working problems also. But not often.

[nickbw]

There are fusible links in the harness to guard against a direct short. Run a continuity test or seek a proper automotive electrician's help.

[hoonk]

There are fusible links in the harness to guard against a direct short.
I have never seen a fusible link in a Volvo. (have seen in in Japanese cars) Can you describe where it might be?

[nsfwaldo]

UPDATE, the courtesy light does actually work, just had a bulb out apparently, so that means the ground is ok since it is also grounded to the low beam. Sooo what else does that leave besides a CEM issue?

[pbierre]

You've isolated the problem to the halogen low-beam on one side. Good. Are you still getting a console message indicating a low-beam bulb is out?
If yes, then your CEM is working (turning ON the 12V relay, and monitoring for balanced current flow to the left vs. right low-beam bulbs). So, now you are just looking for a continuity problem (wiring, connector, bulb) between the 12V relay --> bulb --> ground.

If you're not getting a console message, and one of the two low-beams is lighting up, that indicates that the burnt-out-bulb circuit detection is failing. I'd have to study the electrical schematic to pin that one down...it's never happened to me in 20 years of Volvos with bulb-burnout sensing.

[nsfwaldo]

Oh that’s awsome to hear! Haha. Because yes I am getting a console message! So that does make things a little easier then. I just plugged into vida to see what I could find and I’ll post a picture of what I got. Thank you for that info pbierre!

Do you know which relay is the low beam one? I’ll do some digging as well.

[nsfwaldo]

SOLVED IT!! :D i plugged it into vida and had some CEM errors regauarding the headlights so I cleared them and it came back! I didn’t think it would work but it did. I believe the harsh power draw of the HID’s turning on freaked the CEM out and it shut that circuit down or something of the sort. Thanks everyone for the help!

[pbierre]

Nsfwaldo, you've outgrown the "junior member" status with this story! Congrats