Can the headlight harness take higher wattage bulbs?
A. There has been a report of the wiring getting excessively hot and even the plastic reflector melting when 100W plus bulbs have been substituted on a 1996 specification car. It has been advised that you might need to increase cooling if you go this way by opening up the top vents. I know of a 1997 spec car with 100W bulbs in place with no known side effects but the wiring is a bit on the economic side. A member of IWOC undertook some experiments using light meter readings and found that the light output from 100W bulbs dramatically fell off over only several weeks and further investigation showed that the connector blocks on the back of the lights had started to fail. In my own car I use the Xenon plus H4 bulbs in place of the standard H4 halogens and can say they are certainly brighter (manufacturers claim 30%) for the same power consumption. Note : IWOC now has a supply of these Xenon bulbs available to any Subaru owner at much lower cost than from mainstream stockists via a member
