I've installed Hella Euro Dual Round headlights in my wife's '96 Cabrio. Wired with ND Massive Overkill harness(those guy's suck BTW). I've been through 2 sets of H1's in the low beams within the past month. I clean the bulbs with alcohol before installation. I've done many, many lighting upgrades in previous VW's, Audis & Porsches I've owned and have never seen a problem like this. Power surge possibly??
HELP.......Keep blowing H1 Bulbs
Mar 06, 2004
6 Replies
Your lights are getting too much voltage. We are having the same problem at work with E-class Mercedes. We have to install a new wiring harness adapter that lowers the voltage going to the headlights. It only takes a drop of like 1-1.5 volts to make a huge diff.
I agree...make sure you're getting proper voltage at the bulb before you do anything else.
With the engine running, you should be getting just under 14 volts (I'd say anywhere between 13.5 and 14 is normal).
Also, are the bulbs you're buying a name brand or off brand?
What we are being told at work is that "Most" bulbs are operating at 100% when between 12-13volts. Considering that most newer car alternators put out
14-14.5 volts all you are doing is superheating the bulb causing shorter lifespan for a very marginal increase in lighting.
European type bulbs (e.g. H4) are tested at 13.2V, at that voltage you get the rated power, light output life etc. Most US type bulbs (e.g.
9003) are tested at 12.8V.Craig Williams wrote:
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