upgraded globes...problem

[hairy_boater]

hi everyone

i tried searching but didn't come up with anything usefull...

my mate has an '84 Holden Jackaroo/Isuzu trooper thingi

he recently replaced the 50watt low/60watt high beam globes with 90watt/100watt globes.

the low beams work fine - but the high beams turn themselves off randomly. Was happening last weekend and eventually we just resorted to low beams as the interval between when they'd die was reducing, which we figured was a bad thing.

apparently when he bought them the guy at the shop said he would not need to replace the wiring harness....

possible things we thought of:

- needs relay rated to higher amps
- wiring harness not up to it
- globes working themselves loose [but this would not explain why low beams continued to work?

cheers

tim

[chimpboy]

Mmmm I am guessing but maybe there's a thermal circuit breaker somewhere in the circuit and it's cutting out due to heat.

People looking for brighter lights always upgrade the lamps first when in fact the first thing necessary on virtually every car I've ever seen is to upgrade the wiring.

Jason

[Rainbow Warrior]

Yep thermal circuit breaker in the switch on older cars, answer is to run headlight wires to a relay, then with bigger wiring from the battery through a fuse or larger circuit breaker through the relay to the lights.
The circuit breaker is probably only there to prevent the wiring melting/catching fire, bypassing it and doubling it's load is your choice.
If your wires are too small, your 150w lamps will put out 100w of light and 50w of heat in the wiring loom.