Two new records in one day!!

[pdes]

I have commented here before about the frequency of blowing headlight bulbs on my R1200RT. I have been knocking them out at around every 3-5k miles and they always blow at start-up. However, this moring, BOTH blew at the same time. I think that they were numbers 15 and 16 in the two years (43k miles) since I owned the bike. There's record number one. Record number two is that I changed them both, in the dark in 15 minutes!!

[Bernie]

I think, I would try a different brand of bulbs.

[pdes]

Believe me, I've tried bulbs from all ends of the expense spectrum!!

[JayW]

Something must be wrong. I have only replaced mine twice in 60K miles, and one of those was just preemptive before a multi-week trip. I use bulbs from WalMart. You're not touching the glass of the bulb are you?

 

Jay

[pdes]

Hi Jay,

 

No, very careful not to touch the bulbs. Dealer also said they had no idea what could be wrong but there is obviously a surge of current on start-up. I think others have had this but as I cocver so many miles, it becomes very obvious.

[JayW]

Hi Jay,

 

No, very careful not to touch the bulbs. Dealer also said they had no idea what could be wrong but there is obviously a surge of current on start-up...

 

I think you must be right, but why? Couldn't a current surge be easily confirmed? Did the dealer check for a current surge at start up? It seems strange that 2 bikes with the same electrical systems could have such very different bulb failure rates.

 

Jay

[johnlt]

A good work around would be to put a relay in the line and trigger it off the low beam power and have the lights powered direct to battery. The relay probably wouldn't care about the surge. Might need to put a load resistor there so you wouldn't get a bulb failure indicator.

[Jim VonBaden]

Has anyone looked at the connectors? It has been found on the GS that a loose connector will cause premature failure.

 

The H7 bulbs do not last as long as many others, but should get in excess of 10K miles without too much trouble.

 

Jim

[CoarsegoldKid]

My dealer says he's never heard of them blowing out. Except for the two that blew on my RT - Disintegrated the connectors too. Never saw that either.

[racer7]

Any chance the main connector to the headlight housing is loose?

If manhandled, it might not seat properly because its not well secured at the rear of the headlight end.

 

Try disconnecting, inspecting that pins on all sides show no arcing marks and carefully reconnect.

 

You don't by any chance have a headlight modulator or maybe someone has messed with this connector for some reason?

[Tapatio]

 

HID

 

 

[gordiet]

I was having the same problem with my 06 1200RT until I started using Di-Electric grease on the grounding and connectors. Problem gone! GT

[JayW]

I was having the same problem with my 06 1200RT until I started using Di-Electric grease on the grounding and connectors...

 

Now that you mention it, I too used dielectric grease this last time, but mainly to decrease the chances of the fragile black plastic on the connector breaking apart when I pull it off the bulb contacts next time. Maybe it also extended the bulb life.

[pdes]

Thanks to all for the observations and suggestions. The connectors are tight and in good shape. Not sure of the deep technical analysis carried out buy the dealer but I wouldn't bet on it not just being a look through the tech bulletins. My experience with this dealer is that they are pretty shoddy (they made such a bad job a few months ago that they gave me a free service!). My problem is that the BMW dealers are so few and far between, I have no option but to keep using them.

 

My only other thought is that as I do so many miles at reasonably high speed, the constant vibration is taking it's toll. But having said that, to blow both bulbs at the same time is too much of a coincidence

 

I look out for the grease. Worth a try!

 

[malcolmblalock]

FWIW, I've had two bulbs blow simultaneously, twice. Could not believe it, but it happened that way.

 

I've replaced low-beams about every 4-5K miles since the first bulb blew at about 18K miles. The little plastic things that holds the wiring together have long since disintegrated. I now just plug the wires on the ends of the bulbs and don't worry about it anymore. They do nothing but hold the connections in the right place.

 

I long ago stopped paying much for good bulbs; cost too much to buy the good ones.

 

Seems that a bike costing as much as a RT would not have this problem...

[ka5ysy]

FWIW: I agree that the problem is a voltage spike hitting the bulbs. The only way to verify that is find someone with an oscilloscope that will clearly show the start-up voltage curve.

 

One trick used in electronic devices to avoid spikes is to place a .01uf disc ceramic capacitor across the terminals of the device you want to protect. If you have a ham radio buddy or someone handy with electronics, it is a cheap and easy fix for spikes. Probably 10-12 cents new and most ham geeks have some in their parts box.