Keep blowing out my high beams

I'm now on my 3rd set of halogen headlight bulbs for a 1984 Toyota
truck. It still uses the conventional H4 wiring. However, after about
a month of driving, the high beam filaments break (verified by measuring
continuity on the bulb). The low beams are just fine.


Any clue as to what is causing the high beams to die prematurely?

"O.B." schrieb:
[color=blue]
> I'm now on my 3rd set of halogen headlight bulbs for a 1984 Toyota
> truck. It still uses the conventional H4 wiring. However, after about
> a month of driving, the high beam filaments break (verified by measuring
> continuity on the bulb). The low beams are just fine.
>
> Any clue as to what is causing the high beams to die prematurely?[/color]

Strange.
I only can guess if you have a slight higher voltage or vibration is killing
them.
You may try to use bulbs with higher power (have a thicker filament) or some
of them vibration resistant ones.
Both may be found in agricultural shops (which I recommend for many useful
things on our 4x4s :)

Axel