Hello all -- another headlight question - 04 S type - have high beam only - high beam indicator on dash is on - trying to switch to low with switch doesnt work - lights will flicker, including dash high beam indicator, for less than a milisecond. Am I correct in assuming there is actually only one bulb that depending on voltage to it goes high or low? Both sides are inoperative on low beam and working on high beam - the automatic leveling system is operative. Connector on backside of headlight had current as follows --> I have current on LG wire Wht/Blk with headlights on - Brn I thnk is grnd -- and the Yel/Blu will flicker every 2nd or 3rd time you try to toggle from high beam to low beam. Small wires --> current on Blue / Brn and Blue / Blk and no power on Yel / Blk and Yel / Brn. I am leaning towards BC1 but cant seem to find appropriate diagnostics to be sure.
THANK YOU

 

You have 2 bulbs....high beam and low beam.

Do you have the Xenons?

 

Since he said "automatic leveling system" I'm going to assume that Yes, these are Xenon headlights.

Sounds like a problem with the headlight switch to me. I had a similar problem a long, long time ago - turns out the guys at the factory didn't properly snap in the wiring harness onto the headlight switch/stalk assembly, and it gradually worked it's way loose...

 

-- It is the xenon lighting system - I will take a closer look at the switch wiring connectors - At the risk of sounding TUPID -- there is a bulb in the main part of the headlight assembly tip that is the xenon one - below that is the daytime running light bulb - where, if at all, would the second "low beam " bulb be? I only saw the two and presumede that he xenon was both hi and low beam depending on current delivered to it. Any clarification on this would be appreciated. Someone had actually disconnected the daytime running lights at the bulbs so when I saw that I thought I was all set after plugging them in - but no go there.

Thanks again,

Marc

 

The Xenon bulb is your low beam bulb. The high beam bulb is also your daytime running light - so that cannot be disconnected.

The difference between high beam and low beam is not brightness or current to the bulb - the high beam is aimed higher.

On the other hand, the daytime running lights (which can be programmed in or out through the BC) are just the high beams running at something like 60% power.

Personally, I dislike DRL's, so I had them programmed out on both our MINIs. It sounds like the previous owner of the car didn't know that by disconnecting those bulbs he was also disconnecting the high beams.

 

Correct and to try to clarrify - but I am saying this from what I read in the manuals and not from a car I can check

As I understand the question you think you are showing high beam cuz of the dash lite but your X's are what's on....

- the Xenon is on the low beam only. GEN1 cars with Xenon still have a standard halogen bulb for the high beam and the DRLs run off the high beam at a low power setting. {this is straight out of the Haynes}


DRLs are a feature that can be turned on and off only by one with the magic computer...usually that's the dealer.

If ur X's are on and the high beam indicator is on ... me thinks someone has futzed with the wiring. Buy it used?

 

-- Very interesting - the high beam indicator is on on the dash whether headlights are on or not - also - at times I have noticed lights will stay on UNLESS I cycle the headlight switch once to put them off - The plot thickens here - Thanks for the info - I will keep plugging away - I wonder if whomever disconnected the "daytime" running lights ever noticed they didnt have high beams after they did that.

 

so looking at ur original post

your X's are on and the high beam indicator is on...you toggle the stalk to go to low and things bounce but nothing really changes? Do the other bulbs in your headlight unit ever come on?

This could possibly be a computer issue.....unhook your neg battery cable for about an hour and let the computer die then hook things back up - the equivilent of a classic Windows Hard Boot It's a long shot but what do you have to loose besides reseting the radio code?

I suggest this cus from your descriptions of your chasing this problem it sounds like you'd recognize hacked wires.... On the other hand if your chase has been into spliced and taped wire connections..... HELLLLOOOOOO

{trying to figure this out with a Haynes....if I had a Bentley I'd have the answer by now huh?}

 

Another dumb question - should the lights come on when light switch is turned on even if the key is not on? This one will not come on unless key is in the run position -

 

-- I will try the battery disconnect - have done that on vehicles before - are you sure I am not gonna have to go to dealer to get he ECM re-programmed?
Also, as a side bar I had a bentley Brooklands sedan 1993 coulda used ur help on a while back -==

 

No. At least with my xenons, the lights will not come on, but the car will 'ding' incessantly if the switch is on without the ignition (aka - "turn off your friggin' lights")

 

You'll do no harm in unplugging the battery for a while. It'll take about 10-15 min. A quick 5-sec disconnect wont cut it. I've got to do this on my car from time to time because of issues with the factory nav. About the worst thing is that your trip odometer gets reset back to 0.

 

When I was having the dreaded constantly running fan problem it was a few days b4 I could get to the dealer and I disconnected the battery whenever the car wasn't running. No harm - no foul.

 

Disconnected the battery for 4 hours - still no change in operation of lights - seems more and more the light switch to me - I am going to order one and install it -- I will keep you posted on result -- The low beams come on with switch - the DRL's come on with key on or run - but no high beam operation on either side -- If I actuate high beam toggle aggresively dash light and flicker on high beams can be not for a MILI and I do mean a MILI second -- So as such I am now suspecting the switch after checking out wiring, connectors, battery re-set of BC1 / ECM, and fact thet the self levelers are operating properly. Thanks all for the help -- I will keep checking in case someone suggests something else to check.

 

the computer was a long shot

I agree sounds like the switch

 

Removed the headlight switch - When I removed it the low beams came on - then timed out - I did it twice to confirm I wasnt imagining it -- LOL - seems to me maybe there is a short in the switch to high beam side - so I have one coming -- Will follow up after installation - Oh the switch is a mere $200.00

 

Ouch. Did you at least order it from one of the vendors who offers a NAM discount. I usually go to Classic for dealer-specific things like this...

 

...but not always... some well-equiped indie shops will have a computer that can program chassis computer functions. Near paulgraz and I, Autobahnauto for example. They'll change these settings for MUCH less than most dealers will charge. Especially if you're having other work done.

 

** Ok all, got the switch and replaced it - that fixed the problem ** A way to test it though is to disconnect the headlight switch wiring harness at switch and see if lights time out normally - if so switch is defective.