[GaKu]

Over the last 5 months both the low beams, a back light, a numberplate light and the cabin lights have blown out.   
I have read other older threads about similar issues and there were some suggestions about cleaning the earthing point
Can someone please point out where this is? Pictures in those threads are no longer available.  :

[tw2005]

sure. They're not all the same earthing points though.

[GaKu]

Thanks a lot !!
Is it a plausible explanation that a blown bulb could cause others sharing the same earth to also blow out since there are fewer bulbs "absorbing" a surge?  ?
I say this because after the tail light blew, a week later, the number plate light blew - both share the same earth.
The low beam blew, I drove for a week before replacing it and now the other low beam has blown.

[APD]

Not sure if this is relevant. My full and low beams blew. Identified yellow micro 20amp fuse for 'lights' kept blowing in engine fuse box everytime it was replaced. Replaced larger low and high beam blue lamp fuses and swapped them around with horn and fog blue fuses. The 20amp fuse held and has solved problems for now.

[The Gonz]

As to whether globes are blowing in sympathy at various times, I don't believe they weaken as a result of others blowing. The underlying problem would still be transients due to either poor earthing, poorly regulated voltage supply or both. As for upping the rating of your fuses, yes, that will stop them blowing and it may even be a reasonable fix if the system is drawing a little more current than usual, but there will come a point when the current permitted to flow through the fuse will blow something more expensive instead. Fuses are there for protection, and the designer has chosen the values to provide a given margin.

[Paolo39]

Not sure if this is relevant. My full and low beams blew. Identified yellow micro 20amp fuse for 'lights' kept blowing in engine fuse box everytime it was replaced. Replaced larger low and high beam blue lamp fuses and swapped them around with horn and fog blue fuses. The 20amp fuse held and has solved problems for now.

The fuse ratings are for a reason. If you put higher rating fuse, you risking damaging circuits. I watched video of the guy with BMW, in which higher rated fuse ended up burning wiring loom ( #1 - BMW 520d F10 No Ignition... NEVER USE OVER RATED FUSES! - YouTube - worth watching whole 5 episedes). The blowing fuse sometimes is indication that something on the circuit is not working right.

[nzenigma]

As to whether globes are blowing in sympathy at various times, I don't believe they weaken as a result of others blowing. The underlying problem would still be transients due to either poor earthing, poorly regulated voltage supply or both. As for upping the rating of your fuses, yes, that will stop them blowing and it may even be a reasonable fix if the system is drawing a little more current than usual, but there will come a point when the current permitted to flow through the fuse will blow something more expensive instead. Fuses are there for protection, and the designer has chosen the values to provide a given margin.

I

Thanks a lot !!
Is it a plausible explanation that a blown bulb could cause others sharing the same earth to also blow out since there are fewer bulbs "absorbing" a surge?  ?

Not if the voltage is correctly regulated. That is happening in the alternator. If there is a failure there (voltage regulator) you may get too high voltage or spikes\transients.

Re fuses, they are conductors with 0 resistance. Changing them does not change current flow ( unless they blow)

[GaKu]

I changed the bulb for now. The cabin light turned out to be just a loose connection.
I had 2.5 bar on all 4 a few months back and the ride was pretty hard. Maybe all that shaking caused some bulb issues... dont know.
Down to 2.4 now, will wait a bit before looking deeper into electrical faults

[tw2005]

 

I changed the bulb for now. The cabin light turned out to be just a loose connection.
I had 2.5 bar on all 4 a few months back and the ride was pretty hard. Maybe all that shaking caused some bulb issues... dont know.
Down to 2.4 now, will wait a bit before looking deeper into electrical faults

I run 36 - 38 PSI on all of mine, never an issue on the 16" 55 profiles.

My philosophy on this is first time around benefit of the doubt. What we don't know is hold old those bulbs were or how often you've had to replace them. By the sounds of it, this is your first time.

apart from the dirty contact on the interior, the rest are on simultaneously so lifetime wise they've similar amounts of work. I'd say quality control wise that's to be expected.

Over my years it's been often the case if 1 side blew the other was not far behind. Just recently I've had 2 i30s of mine blow the same headlight a week apart.

I decided to replace both sides on both cars with new globes. I notice just before on one car they were yellowing.

And then a few weeks later, a tail light went Replaced them as a pair again.

If you were replacing the same globes frequently and at shorter intervals  over and over , maybe you'd investigate

[GaKu]

Thanks. The fronts were 18 and 30 months old so not so close. Last time they both were Philips. Now one is Philips and the other osram. Will see how they fare and surely update here.

[nzenigma]

Over my years it's been often the case if 1 side blew the other was not far behind. Just recently I've had 2 i30s of mine blow the same headlight a week apart.

Your neighbours again? 

Probably knocked them off, but  left their dud ones so that you would get the correct replacements before their next raid.

 

[NATHAN_P]

Have you check the charge with a multimeter 13.6 or 14 V . and check also on 2000 or 3000 RPM maybe the regulator is damaged .

[sundiz]

Not sure about petrol, but FD diesel are known to blow low beams often. I changed my low beams to long life bulbs. They seem to work a lot better.

[nzenigma]

Have you check the charge with a multimeter 13.6 or 14 V . and check also on 2000 or 3000 RPM maybe the regulator is damaged .

Regulator  as I said above, have my suspicions. Scope may show spikes better than a meter.