Automotive lighting

Franco Cozzo · 20-07-2011, 11:17 PM

I'm curious if Halogen lights lose their luminosity/intensity as they age or have been on? My Phillips +80s don't seem to be as great as they used to be when I fitted them a few months ago. I've noticed they seem fairly average, not very intense to what I can remember when I first put them in.

I drive with my lights on when ever I drive, so about 2 hours 5 days a week.

Jim Goose · 21-07-2011, 06:51 AM

If the wattage is greater then the factory ones you have installed then eventually you will start to kill wiring quicker... more resistance in the wires means a duller light, less current.
Or if not the case, if they are duller then when installed you have a wiring issue.
Bad earthing most likely.
Pull the plug off the end of the light and put a mulitmeter on it and see how many volts are there.

wrongwaynorris · 21-07-2011, 08:21 AM

The current generation of 50 plus 80 plus and 100 plus do NOT draw any more current . They use a different gas in the bulb to get the extra lux and lumens .

sudszy · 21-07-2011, 08:58 AM

interesting question, Ive never experienced any noticeable dulling of halogen globes as they get older, not like the old sealed beams which could get more yellow as the filament evaporated and deposited itself on the lens of the lamp, that's the purpose of the halogen, to stop that happening.

Perhaps you do need to verify if they are indeed duller, get an identical replacement globe and compare, it may be the lenses on your lamps that are the issue, or that the wiring has deteriorated( low chance). Wiring in good condition should show a voltage drop of less than one volt between the +ve terminal of the battery and the +ve terminal of the lamp when the lamp is operating. Also test the voltage between the -ve terminal of the lamp and the -ve of the battery,(when its operating), there should be zero difference here....otherwise problem in earthing of headlight wiring.

If it proves to be the globe that has got duller, does the globe itself appear to have a deposit on it?

vanman_75 · 21-07-2011, 09:05 AM

My theory is they should get brighter as they age and the filaments slowly get thinner , I would guess voltage drop , either wiring / battery / alternator and a little in reflector deterioration.

Yellow_Festiva · 21-07-2011, 10:21 AM

I think you have just got used to them Damo? Pop in your old globes for a week or 2 then replace them with the new ones you think have dimmed.

See if they appear ultra bright again like you imagined they were when you first installed them.

kempy311 · 21-07-2011, 11:01 AM

Yer as said before they dont pull and extra wattage its just the different gas in the globe, tighter wrapped filaments and different shape glass.

Stick in some new plus 100 and see if they are brighter i would say as they get older they would get duller.

2011G6E · 21-07-2011, 11:06 AM

Quote:

Originally Posted by Yellow_Festiva

I think you have just got used to them Damo? Pop in your old globes for a week or 2 then replace them with the new ones you think have dimmed.

See if they appear ultra bright again like you imagined they were when you first installed them.

Unless there is indeed a fault with the bulbs, I believe that's your answer right there. Simple "familiarity breeds contempt". You really notice the brightness when you purchase them and for some time afterwoods, but it's just human nature to get used to something the more you see it, and after a while you won't notice it anymore.

demood · 21-07-2011, 01:08 PM

Make sure you lenses are clean too, you'd be suprised how much difference that can make!

FTE72 · 21-07-2011, 04:59 PM

They will get a little dimmer with age(don't we all?) due to the breakdown of the filament being deposited and coating the inside of the lamp(not headlight assembly).
Have a look at any old halogen lamp or even old sealed beam, you might notice a silvery appearance. All lamps have rated life, they may last longer but generally the rated life means how long it will output at stated luminance.

Franco Cozzo · 21-07-2011, 08:29 PM

Quote:

Originally Posted by Yellow_Festiva

I think you have just got used to them Damo? Pop in your old globes for a week or 2 then replace them with the new ones you think have dimmed.

See if they appear ultra bright again like you imagined they were when you first installed them.

This is probably it LOL.

Its either that or because I haven't washed my car for ages that dirt is on the covers.

Thanks for the tips though, I'll check Dad and Mum's car for voltage drop because their lights suck big time compared to mine, could be reflector design though.