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2007 K1200GT tail light bulbs

cdavis

New member
My new-to-me (3 months) 2007 K1200GT seems to have an appetite for tail light bulbs. I've already replaced them twice after the warning light came on each time. Upon removing the bulbs I found the bottom center contact is flat, not pointed as on a new bulb. It looks like there is arcing or something similar going on and eating away at the contact.

Anyone else have this issue, or know what the cause/remedy might be?

The bulbs are P21W / 1057's.

TiA
 
Scuff the socket contacts with 220 sandpaper. Don't try to grind them down, just scuff enough to remove possible oxidation.

Are the bulbs really dead or only the contacts are messed up?
 
That sounds more like a socket problem - typically, there is a little spring inside of that, to maintain contact between the socket's center and the bulb's tip, but it's Not supposed to wear down the bulb that quickly (even though the contact on the bulb is soft).
Vibration (or lots of rough roads) may cause the contacts to "make and break"; this causes the arcing, and the sudden loss of, and then application of, the 12 volts causes extreme temperature cycling of the filament, causing its early demise.
Inspect the socket and its mounting, including the surrounding tail section, and all relevant wiring. Sometimes the problem is actually on the Ground side - but it shows at the +12 (bulb tip) side because the bulb's ground is much larger and less likely to lose contact.
 
Last edited:
Thanks for the responses.

The bulb filaments appear to be fine -- just the contact at the base is a problem.

I am going to try to increase the spring pressure of the socket on the bulb, and remove mild surface corrosion on the socket contact.
 
Increasing the spring pressure (I presume by pulling it a tad) will flatten the bulb's center contact more.
It may improve the contact (for a while), but I'd look for the "Root Cause" of the make-and-break.
 
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