Let there be light, please!

[Dolomite16V]

I thought I'd upgrade the headlight bulbs on the Dolly 1300 as the stock ones are scarily bad at this time of year and the car is getting used all winter. I fitted a new pair of 60/55W ring halogen bulbs with the correct metal base fitment and connector prongs, but they don't illuminate at all, if I refit the old tungsten ones all is well again - albeit chucking out yellow light.<br>
Any ideas?<br>
Alex.

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[davepoth]

I reckon it's the wiring and you aren't getting enough power to the bulbs to light them. Since the old bulbs are much lower rated they don't need so much power to put out (a bit of) light. Check the voltage and current ratings at the bulb connectors and see what you get.

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[tinweevil]

Can't think of anything that would cause total failure, as Dave suggests, check your voltages. A bad joint at the connector behind the valence is common. The law of sod could easily be at play making it appear to be the new bulb. Is the dad on both high and low?<br>
<br>
I recommend fitting a relay on you dipped circuit or better still both circuits. If memory serves the standard bulbs are 35/55 so you've almost doubled the dip current all of which flows through the stalk. Soon as you get a bit of dirt in there increasing resistance you'll melt the plastic around the contacts. Happened on mine soon after I got it and it was running standard lamps.<br>
<br>
Tinweevil

<p>1978 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/704">Dolomite Sprint</a><!--EZCODE LINK END--><br>
1972 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/754">Spitfire IV</a><!--EZCODE LINK END--><br>
1968 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/705">GT6 II</a><!--EZCODE LINK END--><br>
1973 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/755">Dolomite Sprint</a><!--EZCODE LINK END--><br>
39 anorak points on the Nicholas scale<br>
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[dollyboy]

both dave and julian absolutely correct, duff connections are common, cable size to the bulbs will probably need to be bigger, relay highly recommended, dont see why the new bulbs wouldnt work at all unless they're duffers. even if the filament in the bulb looks in tact, doesnt necessarily mean the bulbs good, so i'd check the bulbs straight on the battery first. careful with the wires though.<br>
<br>
low voltage would mean the bulbs would be dim. If the supply voltage is ok and the cabling's the source of the voltage loss, or theres a short at the bulb end somewhere, you'll simply melt the wiring and/or the switch (additional fuse good idea here). if the voltage is that low that the bulbs dont illuminate at all, you need a new battery, but how come the old ones work when you put them back??! battery sounds ok to me.<br>
<br>
oil/grease/dirt causing bad earth at new bulb possibly? clean the bulb base with a bit of cloth or kitchen roll soaked in bit of light solvent, then make sure its cleaned off before you try again, but make sure you hold the glass part of the bulb with a cloth. (i have no idea why everyone recommends that with halogen bulbs, but i'll jump on the band wagon - suggestions welcome...)<br>
<br>
<!--EZCODE EMOTICON START :) --><img src=http://www.ezboard.com/intl/aenglish/im ... /smile.gif ALT=":)"><!--EZCODE EMOTICON END-->

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[Silvery]

Never touch a halogen bulb as the natural oils on your fingers will create hotspots on the thin glass, causing localised overheating and premature failure.<br>
<br>
Of course, they'll only fail through being fingered with naked hands, and not ever through on/ off cycles burning traces of filament away, vibration and shock on today's delibaretly bumpy roads, a combination thereof...<br>
<br>
Although I can see the logic behind never touching the bulb, given the cost of the damned things and the other factors affecting lifespan, so long as I'm not covered in oil or lm2 when fitting them I don't worry.

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[Dolomite16V]

Thanks for all the input, I'll get going with your suggestions and see what happens<!--EZCODE EMOTICON START :D --><img src=http://www.ezboard.com/intl/aenglish/im ... /happy.gif ALT=":D"><!--EZCODE EMOTICON END--> <br>
Alex

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