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Semi-frequent tail light failure - '07 RT

greggsnider

G Spot
My right tail light has, once again, burned out. This happens seemingly 1-3 times per year.

I use good quality replacement bulbs, and the left tail light has only burned out maybe 1-2 times in 5 years. The right tail light is completely out, for both normal operating and for braking. Oddly, the dashboard warning indicators - the 'lamp-out' icon and the yellow ! indicator - only come on when I hit the brakes. Otherwise, the dash doesn't show the lamp as being out.

Any thoughts on a) why the right one (and only the right one) burns out so often, and b) why the indicators only come on when braking? I assume some electrical issue, but I'm not sure where to start. Any assistance would be appreciated. Thanks.
 
It's out for both tail and braking because it's the same filament. Braking brightness is accomplished by increasing voltage. Clearly that's a sophisticated system not likely to respond well to user modifications and maybe likely to fail another reason as well. Requires dealer analysis using special tools IMHO.

In any event I'd think both bulbs should be exactly the same and "quality" bulb means the German bulb sold by your dealer.
 
Bulb life can be decreased by excessive vibration. I'd check to make sure that the right-side light housing and bulb socket are both mounted firmly, and that the bulb is grasped firmly by the socket as well.
 
I'd be suspecting vibration of a connection or a loose connection at that tailight. (I've seen a couple lose spades on RT tailights, for example)

Please tell US what brand and bulb number you are using. (More than 1 person has accidentally used a wrong bulb thinking it is correct or equivalent when it is not).

Also, are you certain the bulbs are burned out - have a broken filament?

Sometimes bulbs pound the lead connector bead on the botton flat enough (from vibration) to lose a connection to the socket.

Although the previous comment about using BMW-supplied bulbs may seem odd to you it contains a nugget of truth- on average the best and most consistent bulbs come from European makers, many of whom have relocated their plants to eastern Europe. And there are a whole lot of medocre to junk bulbs coming out of Asia as well as direct counterfeits of better euro stuff...
 
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