2005 ST head light bulbs KEEPS melting its front shield ??? HELP!

Dr. Curve · 12:24 PM

Hoping here that others will have heard of, seen, or know what the problem might be.........

The bike is a 2005 ST that had run perfectly.......until the time came that, when it had a low battery, had not been started in a while, but then was started, its battery now jumped from a running car engine. The bike cranked, all was well........but rather quickly over a period of weeks, the area of the clear light lens, directly in front of the stock blub that came with the bike............started to melt.

That is.......when the light is on, the lens starts to get hot very quickly, discolors, crinkles, and eventually starts to break the clear shield in a area about the size of a fruit jar lid.........directly in from of the bulb which is about 3.5 inches behind it in the light carrier.

Took to dealer........they checked everything......found nothing........had another ST to compare to sitting right there...........alt output on both max at 14.15 volts.

They replaced the battery, the shield lens, the bulb........and sent the bike on its way. Sure enough, after a time of several months........the same area of the new lens started to discolor and melt down to discolor.

Another shield was ordered and put in along with bulb. Shortly it started again?????

BMW says that they will not warranty it because the bike was jumped by a car that was running and they have no way of knowing what kind of voltage went into the system.

When the light is on and the engine of the bike is running........the bulb looks to be way too bright, even though is is stock.

I have suggested that, while the ABS is allowed to suck all the current up to the alternator max of 14.5 when the need arises...............line voltage to everything else is regulated to a more normal 12.8 to 13.2 volts...........and it may be that the jump off caused a problem in the line voltage to the bulb now becoming too high.

Very frustrated shop, owner, and bike............

Any ideas as to what may be causing this and how one might go about tracking down this problem of a ST that is melting it's head light lens over time>\???????????

Thanks brothers in advance.........ever heard of, or seen this before?

MaineRoads · 10:41 AM

Whats the voltage at the bulb? Take it out and test it while running. Bad ground to headlight is my guess.

Dr. Curve · 06-01-2011, 10:49 AM

Steve, if it is above the 12.8 to 13.2 threshole..............meaning too high..........where would one then look to see WHY it is too high? The problem started at once........after the bike was jumped started with a running car engine. Where would the fault lie........which component of the BMW "brain" network? We are using a BMW ETK tester. Will check and get back to you tomorrow. Thanks for the interest Steve. Anybody out there ever hear, or see this problem?

MaineRoads · 06-01-2011, 10:56 AM

Look where the ground for the bulb is. I wouldn't look at a component as much as a bad connection or a worn through wire that grounds the bulb.

jduke · 06-01-2011, 11:00 AM

Jim, unless you by passed the Can-Bus system, you've probably fried something inside the ZFE.
I think I have a good one at home, I'll check tonight and let you know.

SergioK · 06-01-2011, 11:08 AM

I dread the day when BMW decides we (motorcycles) need to 'register' a new battery after the brain has detected a dead battery a la current 3' 5' 7' Series cars.

I too vote for something amiss electronically if you are getting to high a voltage on the light.

Dr. Curve · 06-01-2011, 11:15 AM

Thanks Jerry........that is what I think as well and what the owner does not want to hear. We do not have the Factory EMW checker unit........but realize here fully that the ZFE is UNIQUE to each VIN number and after installation must be programed from the computer. LOTS of money involved, so hoping for some other type of problem. We know, or think we know, that it the voltage is high, like directly what the alt is putting out (14.1).........we have a internal problem that will not be fixed by anything we can do except replace the ZFE. Fingers cross for us if you will and still hoping someone will put together a R11S run only............so you and "Got Road" can lead. Take care and thanks.

rs1tc · rs1tc's Garage

If you knew the output voltage output of the car that jump started the bike you should be able to calculate how much went into the bike. I think if you use engine rpm, alternator output at said rpm, calculate for resistance of the jumper cables that should put you in the ball park?

Also, I avoid jumping bikes with cars, if anything I would use the car to do a quick charge on the bike battery ~5min, then disconnect the jumper leads and try and start the bike. I could be wrong though.

jduke · 06-01-2011, 11:34 AM

Quote:

Originally Posted by Dr. Curve

Thanks Jerry........that is what I think as well and what the owner does not want to hear. We do not have the Factory EMW checker unit........but realize here fully that the ZFE is UNIQUE to each VIN number and after installation must be programed from the computer. LOTS of money involved, so hoping for some other type of problem. We know, or think we know, that it the voltage is high, like directly what the alt is putting out (14.1).........we have a internal problem that will not be fixed by anything we can do except replace the ZFE. Fingers cross for us if you will and still hoping someone will put together a R11S run only............so you and "Got Road" can lead. Take care and thanks.

I believe if the ZFE's are both for a 2005 ST, you can swap them and then see what works and what doesn't work. I've seen ZFE's for the same model swap out and everything work fine, but I've also seen where things like the horn or fuel gauge not work and the bike had to be plugged into the dealer computer and "initialized" for lack of the correct terminology BMW calls it.

dee jones · 06-01-2011, 11:34 AM

Jim I wish I could help but I have never had this problem with either one of my ST's. I have actually jumped both of the bikes and as of yet have not had any adverse effects. Hopefully you'll get the problem resolved quickly and cheaply!

jduke · 06-01-2011, 11:35 AM

Also, you mention LOTS of money, not my experience. Orlando BMW charged me one hour tech time to "initialize" the last one I did.

jduke · 06-01-2011, 11:35 AM

Dee, was the car engine running when you jumped your bikes off?

AndrewA · 06-01-2011, 11:48 AM

The bike is self-immolating.

dee jones · 06-01-2011, 11:55 AM

Jerry yes it was.

Dr. Curve · 06-01-2011, 12:37 PM

Thats a thought.............but what is it protesting?

That engine looks like it had good food, plenty of water, regular check ups, and clean open air flowing its breather.........why in the World would it want to NOW "self-heat it's own self"........... into the used parts bin of life.........

When the possibility or good open roads with blue skys above are waiting.......her sleek silver skin soon to be running plenty of pressure in both paws, her smooth engine stroking cool as the horizon gets chased once again.................is being offered by a potential new owner like me?

Why burn up now, send us a sigh that we can figure.

cageyar · cageyar's Garage

The ST headlight includes side lights that the S and GS don't include - are the side lights operational or did they fry in the jump?

Guest24 · 06-01-2011, 01:34 PM

Don't know if it could happen twice; but, my R12RT started blowing all the headlights. Turns out that the positive lead had chafed through the insulation and when it arched to ground the lights would get zapped. It the bright was on at the moment it got zapped, also. Just a thought.

AZ-Twin · 06-01-2011, 02:23 PM

Quote:

Originally Posted by Dr. Curve

Thanks Jerry........that is what I think as well and what the owner does not want to hear. We do not have the Factory EMW checker unit........but realize here fully that the ZFE is UNIQUE to each VIN number and after installation must be programed from the computer. LOTS of money involved, so hoping for some other type of problem. We know, or think we know, that it the voltage is high, like directly what the alt is putting out (14.1).........we have a internal problem that will not be fixed by anything we can do except replace the ZFE. Fingers cross for us if you will and still hoping someone will put together a R11S run only............so you and "Got Road" can lead. Take care and thanks.

Are you saying that the a normal function of the ZFE module is to farther reduce the voltage output of the charging system before sending it to the headlamp? You believe the issue is the ZFE, and not an issue with the voltage regulator/charging system?

I am not saying it ain't so, but it sure sounds odd, but these are pretty odd bikes.

I would point my finger at the charging system, not the ZFE. I will do some voltage check at the headlight and battery on my R1200S with the engine running and see what I get.

jduke · 06-01-2011, 04:09 PM

Rob, my understanding is the ZFE controls the lights and other stuff, so when I read Jim's post that was my first thought. But I agree, test everything suggested first. I have a ZFE he is welcome to swap and see if it makes any difference.

Dr. Curve · 06-01-2011, 05:08 PM

AZ, in a regular world the problems would stay separate and therefore could be worked on by themselves......voltage regulator........alternator......timing.......ect. In the newer Can-Bus system things seemed to have changed. The bike is charging perfectly, no other lights or functions have been affected, the engine is firm, ect. The ONLY thing is that the front plastic (lexan?) keeps getting so hot from the single bulb area in the headlight........that the clear plastic crinkles, starts to turn brown, and eventually surface cracks. Nothing else on the bike is affected. My understanding is that the ABS system is "allowed to take all the current it needs......up to the 14.1 max the alternator is putting out...........BUT......everything else gets to use just the line output after the built in regulator reduces it to 12.8 or so. Because the bulb is getting too hot it must be getting more voltage than necessary.........but they have not checked at the bulb yet. Tomorrow, with the motor running. If you have any ideas AZ......we will try them on this bike. Already this has helped because Jerry has seen how some units interchange quickly, though used, and may, at most only need to be reprogramed at the dealers computer. If I can fix this problem I may purchase the bike which seems quite nice.