Can stock H13 12V 60/55W bulbs be replaced with H13 12V 100/80W bulbs w/o issue/problems - my passenger low beam says otherwise. Checked switch by reseating, and replacing with a new switch; but, still no passenger low beam. What am I missing?
Ed, if we are talking incandescent bulbs, (not HIDs) and I'm doing the math right, 60 watts draws 5 amps at 12 volts and 100 watts draws 8.34 amps at 12 volts. Factory wiring is notoriously light in terms of wire gauge. If you only used them for a short period of time you probably wouldn't have a problem, but on a hot summer day with a long run time you could possibly burn a wire or a connector or blow a fuse.
Based on your level of experience judged from the questions that you asked, your best bet is to let a technician troubleshoot the issue. It is hard to offer good advice without being hands on and seeing what's going on. Others may have different opinions, but that is mine for what it's worth.