Headlight tech

fweddy · Post by **fweddy** » Thu Oct 04, 2007 8:50 pm

Who knows much about headlights?

This Hiace I have has blown low beam on one light. I pulled it out and the sealed beam round light (12v) is the same shape as my morris minor headlights (also 12v) but when I put one of them in (or two) they get white vapour and wee flames and then blow.

Is that likely to be something with the wiring of the vehicle or are the bulbs different? Voltage is the same but is it likely to be wattage or amps or ???? There is no coding on the bulbs that makes any sense to me.

Just don't want to go buy a new one and blow that too if its the wiring in the vehicle... I guess I should try the other side but my stash of bulbs is diminishing!

mercutio · Post by **mercutio** » Thu Oct 04, 2007 8:55 pm

how old were the old sealed beam units on the morrie had they been sitting around for a few years doing nothing if so it isnÂ´t surprising that they blew

fweddy · Post by **fweddy** » Thu Oct 04, 2007 9:04 pm

mercutio wrote:how old were the old sealed beam units on the morrie had they been sitting around for a few years doing nothing if so it isnÂ´t surprising that they blew

Yeah most likely fairly aged. I think I have one there that was used more recently - maybe I could try blowing that one too

tallsam66 · Post by **tallsam66** » Thu Oct 04, 2007 9:17 pm

Im just guessing but id say they are no longer sealed & air has got in & causing them to blow...just as a household lightbulb blows if it leaks.

wjw · Post by **wjw** » Fri Oct 05, 2007 7:05 am

Go buy a standard hi-low bulb from supercheap... solder three wires on and fudge them back to the existing connector and see if that works ok. If so go buy replacement sealed beam unit ;-)

Steve_t647 · Post by **Steve_t647** » Fri Oct 05, 2007 8:46 am

IO cant see how an electrical fault could cause you bulb's to blow, spotlights with HID maybe but unless you have too much current to the bulb (it is a 12v system).

I would do what WJW suggests or swap the working bulb into the non working side to see what happens.

fweddy · Post by **fweddy** » Fri Oct 05, 2007 10:50 am

Spoke to my auto sparky and he reckons that if they are putting of the while vapour and blowing, the bulbs must have holes in them. Seems funny to me that all of them are doing it eventualy. I tried one in the other side of the van (which has the good headlight) with the same result.

Might just go buy a new bulb for $26 odd

fweddy · Post by **fweddy** » Fri Oct 05, 2007 5:31 pm

Managed to get one of my Lucas bulbs to hold out, and it is doing the job ok.

Failed a Wof on one tyre, door hinge and tail light lense.

Any one got a cheap 8 ply 185 R 14? just wofable ok