I found out another cause of dim headlights on the 1995 Subaru, and this problem seems to afflict other Subarus of that vintage jusging by your forum. So far : new bulbs, defective fuse recepticle or fuse, and defective plug (in back of the bulb) have been proposed. None of these remedies worked for me. Item number one: if one or more of the four posasible filaments is different (dimmer or brighter) than the rest, you can omit the bad ground explanation, it seems to me. By the way, exactly where IS the headlight ground?
All wires lead to the under-hood fusebox so obviously there is a plug somewhere under it, or else inside the fender. The plugs are UNDER it. Pull the fusebox, get the wiper fluid reservior free and on top of the motor so there is some room, remove dust cover, bend the bundle of wires so that you can work under the fusebox, remove white and brick-colored plugs to get access to headlight plug latch, remove Headlight Plug which is 'way in the back, i.e. motor side of the fuse box, now on bottom because the box is tilted. Plug latch goes against the plug, not out from it, to free the catch. This plug is stiff. AMAZING: the whole thing (male prongs under the fusebox ) is corroded.
Squirt some "Blaster" in the female side (do not fear; this conducts electricity) work the two sides of the plug together to scrape corrosion off, reassemble the whole thing and the lights will work yrs Wilder