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[VN] Blowing Headlights

firstvn

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Hey,

So this isn't the first time it has happened, but it also isn't an always happening occurrence.

The other night when I was heading to overnight shift, I got about 10m from the driveway, the "Battery Warning/Check" light came on and a couple seconds later my lights went bright then went out. High beams were fine, but other than that I was driving blind. Couldn't do anything about it as it was dark, so just had to take back streets with high beams til I could get off work in the morning.

Just replaced the lights today and both bulbs had a black residue inside (presumably from the filaments blowing), and could clearly see that the filament was broken.

This has happened before, maybe a year or two ago, and the exact same thing happened. Warning light comes on, lights go really bright for a second, then blow.

The battery itself is a couple months old. I also replaced the regulator on the alternator a few months back as that was causing problems previously.

What could be causing the sudden "surge" to the headlights?

Any suggestions are appreciated, don't want to keep having to spend money on new headlights all the time. And definitely don't want it happening again out on the highway.
 

Jxfwsf

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either the alternator is buggered (sudden higher voltage surge and charge warning like coming on would be causing me to replace the whole thing, probably something else internally wrong with the alternator)
bad connection to the battery, but even so the alternator shouldn't over volt to much under load with lights on, but this is a possibility.

you're lucky all it did was blow a couple of globes, i wouldn't be driving it till it's fixed or next time it might decide to take out the ecu and any other electronics connected to it, the stereo and your dash cluster.
 

immortality

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I too would suggest the alternator is most likely the problem as it controls the voltage. Seeing as you have replaced the regulator maybe there is problem with the actual alternator (badly worn slip rings or failing diodes etc0.

It may also pay to check the alternator voltage sensor wire, if this is in poor condition it can cause the voltage regulator to play up, also check the charge cable/connections. If the cable has a bad connection the regulator would see that as a voltage drop @ the battery and increase the alternator voltage to compensate. Check the connections as the battery and the alternator, also check the crimp joints and look for heat damage etc.

Maybe see if you can borrow another alternator from a mate with a Commodore.
 

bundybear75

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On a side note it is always a good idea to carry a couple of H4 globes in the glovebox for this instance. 5 min on the edge of the road replacing your lamps could avoid a fine or even worse an accident by dazzling the oncoming traffic
 

DJ_Cosmic_Fire

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What could be causing the sudden "surge" to the headlights?

Any suggestions are appreciated, don't want to keep having to spend money on new headlights all the time. And definitely don't want it happening again out on the highway.
Surges like this indicate over charging, but check & clean all main the earth's & positive connections (ie battery to chassis, positive alt to battery, earth from alt to engine, etc etc). Alternator needs replacing with a new unit, easy & cheap to do at home - 30mins & you're done, will be about 160-180 for a Jaylec 65-1000 alternator (it's not chinese junk)
 

Jxfwsf

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chinese junk huh? name something these days available on the shelf that isn't made in china...

nb: on shelf, not off the internet.

(sure you buy the cheapest of the cheap because you're a tightarse to save a few buck for something on the internet.... you deserve it, but buggered if i can find anything not made in china with decent qc checks for most brands these days) but it's hard to tell the knock off from the genuine now, most people couldn't pick it.

In most cases you pay 1/4 of the price for something that lasts 1/2 as long, end of the day you still come out ahead (now, what's stopping you from manufacturing high quality parts made right here, under your supervision and quality control? an alternator regulator is a very basic thing.....)
Face it, we're a throw away society that doesn't care where something comes from, so long as it's warranty can be honored now!! when we want it fixed.
 
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FXST01

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What size fuse do you have on the low beam lights?
 

Brett_jjj

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Check all the main earths, the main engine block earth point and the main body earth point. I saw this happen once before because of bad earthing, (persumably) playing havoc with the regulator.( I dont remmeber what car it was now) , but the alternator/charge light would come on, and then one or both of the headlights would blow a second or two later, it would also blow the brake lights if the footbrake was pressed at the time the alt light came on. Something (probably the regulator) must have been letting a big voltage spike through from the alternator to do this..The guy had tried a couple of diffeent alternators/regulators with the same thing still happening.. The break in the engine block earth wire was found and fixed, and extra earth wires were added to both the engine block and body from the negative battery terminal.. the problem never returned after that was done.
 
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