i recently bought some new 80/100 watt heatlight bulbs for my 99 4runner without doing research on the site. they should be here tommrow. so i started looking tonight and found that some people suggested upgrading the wiring harness. some people said that theirs have worked fine without any problems at all, and they are using the factory wiring. please let me know if you think i need to upgrade or not.

 

First thing you need to know is- are they really 80/100w (and therefore illegal) or are they Xenon (if you're lucky) blue-colored bulbs with "claimed" 80/100w performance? If they are really 80/100 you might really consider upgrading the wiring. If they are the new-world-we-live-in advertising-department-rated bulbs, don't worry - they won't draw more than stock and won't even be as bright as your stock bulbs were either most likely...

 

well i ordered them out of performance products and they are the Delta hyper white bulbs. they had one at stock wattage then they had the higher wattage ones. i ordered the higher wattage ones.

 

Sounds good. Rarely does a failure of the wiring occur, but since it's easy to upgrade the harness it's not a bad idea.
Sometimes the failure (if any failure occurs) is around the bulb holder from the higher heat of the bulb.
(In my post I was referring the recent trend in "asian import" bulbs that say something draw 55/60 but "perform like" 80/100. They lie....)