Exploding light globes

[froop]

After upgrading the wiring the loom for my headlights just two weekends ago, and installing the driving lights last weekend, and feeling all satisfied with myself, I just went to park my Jeep round the back while I'm up on the Gold Coast next week. In the 5 minutes it took me to drive around and open the gate (with high beams and spotties on) my right side headlight globe literally exploded - shards of glass in the light, and a dulled reflector (presumably from a dusting caused by the shattered globe).

What might be the reason for this?

I've re-wired the headlights to draw directly from the battery (5mm wire, both 12V and GND), with the old plugs driving a new relay (one relay for both lows, one for both highs). The new globes are 80w/100w (or is that 100w/80w?)

I didn't touch the globes at all when I inserted them, so is there anything else aside from dodgy light globes that could cause this? What globes have proven themselves amongst the Ausjeepoffroad crew?

[maddog]

Were they really cold? Perhaps really cold to really hot temp change made them explode?

[LEXX]

Froop, do you have acircuit breaker inbetween the new relays and your bat? Easy and cheap insurance, also look at a globe "preheater" which is fairly essentialo down here in the cold we get.

LAZ is a lighting GURU and he is certainly worth a PM m8 to sort your problem out for you, but honestly here in VIC it is not uncommon for headlights to "explode" or crack.

[Laz]

Hi Froop,

Heard my name (not being used as a swear word for a change

Dude, that Blows! litterally. while YOU may not have touched the bulbs, you certainly cannot guarantee that someone else didn't, I always use a microfibre cloth to polish up new globes - removes all residue etc.

Bulbs dislike moisture, and DESPISE oil/hydrocarbons of any type - get an airline into the "Dulled" front reflector and blow out any crap in there, now get a hair-dryer and gently heat up the headlight from the glass (slowly) they can handle a shiteload of heat and this will vaporise any moisture in the case - to ensure it's clear - let it cool down for a while and check for condensation.

With respect to fuses - nah go an inline breaker - 30 amps is heaps for your headlights. When overloaded or shorted it simply "*winks" till the hsort is removed or the breaker burns out - which takes a while

*Winks: There is a bi-metalic strip in the circut breaker that "bends"when heated (excessive current) effectively "breaking contact". These units are also known as thermal trips.

=== freely given - hence it's value advice follows ======

Brands of globes - well this is a interesting topic, basically the higher the rating of the globe, the shorter the life, as different inert gases allow the tungsten fillament to "burn" at different colour temperatures.

2400 Kelvin is about average for most car headlights - looks significantly yellow - these lights have an average life in excess of 3000 hours

3500 - 4000 Kelvin is considered to be a "white light" these lights are typically packages as Plus 30's (%) have a av lifespan of 1500 hours

4500 - 5400 Kelvin is considered to be a "true daylight" globe, typically packaged as plus 50's (5) have an average lifespan of 500 hours (these are my favorites as the human eye is far more sensitive to blue light, this also works well with the refractive index of most prismatic based reflectors on street signs and line markers)

now onto the specialist lights

6000 - 7000 kelvin are commonly known as "Super blues"as they are headed more up to the blue end of the spectrum, these lights are packaged as Plus 50's or higher 70's etc, have a lifespan not exceeding 200 hours - expect to blow one of these suckers every 6 months!

8500 - 9300 kelvin are Rice boy specials known as Ültra blues/ or Ultra violets, bloody annoying to drive towards, expect lots of flashing from other cars even on lowbeam - you must have alot of "bling"to pull these off! also note the rated life of these suckers is 5 mins or 5 miles - whichever somes first.

IMNSHO (basically i'm not humble about lights) Narva make great bulbs, for standard wiring looms they have a great H4 (TJ's, XJ's etc) +50's, good rated life 500+ hours, exellent beam pattern, krypton gas - The NARVA +50 (55 watt lowbeam /60 watt highbeam) - these will outperform a IPF 80/100 in the standard loom EVERY TIME.

If you have been tuned into insane FM (my favorite station) and have upgraded your loom to 3mm or better wire (5mm will carry better than 60 amps - so this is EXTREME) then you can run a IPF 80/110 - nice chrisp white light (4500 K) long life at 1000+ hours.

If you were to be driving OFFROAD only, then a set of 110/130's work BLOODY GREAT - but only with the IPF loom (or 3mm + wire)

I have also had great runs with both Hella and Osram, but I allways err toward Narva's due to the light pattern.

Laz'- the illuminary one. . also a Jerk

[maddog]

I seem to have blown one of my 100/170's after only 6 or 8 months. I think I might downgrade to 110/130's and see if they last a bit longer.

[froop]

Thanks for the verbose response Laz. Might do me a little more looking at the different globes on the market, and looking at kelvin rating as well as wattage before getting replacements (I'll throw the factory ones back in after I clean out the mess from the reflector and lens).

The driving lights are wired through the fuse box hanging off the second battery, and for the hi/low beams I have relays with 30A fuses. Haven't actually checked the fuses to see if they went too.

BTW, I've wired with 4mm, not 5mm as I said in my original post. So not *quite* so extreme

What exactly is a globe pre-heater, and where does it fit in the scheme of things?
It is quite possibly heat related, since it was late in the evening, and I turned the high beams on pretty much straight away.

[OzJeeper]

Globe pre-heater? Visions now of a little man running around the interior of a headlight with little woollen booties to put on the globes so they don't get cold...

Seriously - thanks for the great write up Laz. Wish we had an archive for this type of valuable info...