SRAD keeps blowing headlight bulbs

[SMOKEU]

I have a headlight bulb blow about every 600-1000km on my bike and I can't figure out why. I disconnected the headlight plug of the blown bulb and started the engine and the output voltage is around 13.3V when the engine is idling, but the voltage drops to around 12.5V at 4,000RPM. The voltage appears to drop as the revs increase which seems a bit strange to me.

[p.dath]

I have a headlight bulb blow about every 600-1000km on my bike and I can't figure out why. I disconnected the headlight plug of the blown bulb and started the engine and the output voltage is around 13.3V when the engine is idling, but the voltage drops to around 12.5V at 4,000RPM. The voltage appears to drop as the revs increase which seems a bit strange to me.

Any chance you are handling the bulb with your bare hands, leaving human grease on it, causing abnormal heating and cooling patterns, and premature failure?

[darkwolf]

That sounds like a voltage regulator issue to me... how's your battery - does it get warm after a while (though I suspect this would be more prominent after overvolting the battery)

[SMOKEU]

Any chance you are handling the bulb with your bare hands, leaving human grease on it, causing abnormal heating and cooling patterns, and premature failure?

I'm always careful to never touch the glass with bare skin.

That sounds like a voltage regulator issue to me... how's your battery - does it get warm after a while (though I suspect this would be more prominent after overvolting the battery)

The battery never feels warm to the touch and the battery voltage is actually a bit on the low side. It's usually under 13.2V with the engine off after a decent ride.

[Coldrider]

I'm always careful to never touch the glass with bare skin.

just wipe the bulb with pure alcohol if you do.

Bulb blowing indicates a voltage (high) spike, check earthing and corrosion before the hard work of regulators and such things.

[Akzle]

still.

yes. filthy-white-guy-hand-grease. wipe bulbs with meths on a rag/newspaper to fit. and don't touch em after.

does sound like charging issue for sure. although i'm not sure if your reg things it's "clever" and only puts a float charge into the battery while it's at/over normal volts.
or that the rest of your circuitry causes such current draw that the voltage drop caused is caused.

[tigertim20]

ok ok ok.

before you get carried away with all the obscure possibilities, check the basics. go over your wiring looking for anything corroded, or any earths that might be shorting, or any plugs that might be letting moisture in.

Buy some dielectric grease, and some electrical cleaner. Open every plug on the bike, clean them out with electrical cleaner, then use the grease. this is something you should be doing on an older bike as part of general maintenance anyway!

after that, start looking at obscure shit.

[spanner spinner]

Your bike has a charge issue as the charge voltage should 14 to 14.5 at 4 to 5 thousand rpm. Low voltage will cause the bulb to quickly fail as it runs at the wrong temputure. But as a long shot check the headlight mounting pins that slot into the front fairing frame. If these are broken (they brake just in general use due to vibration caused by the superior quality of NZ roads) they cause the headlight to vibrate causing the bulbs to fail.

[DEATH_INC.]

How many wheelies are ya doing? The high quality chinese bulbs we get nowadays last about 2 seconds when ya do wheelies...