How do I make my headlights' high beams brighter?

My best Advice is to get some Sylvania Silver-star bulbs. They make a much "whiter" light than the factory spec bulbs do (which I think looks kinda yellow). You may also need to re-polish the outside of your lenses, as the plastic does oxidize over time and reduce the transparency of the lenses.

Nope it is not your switch, many vehicles have a lightswitch like you have, you change from dimmed to bright light, and before you release the switch, BOTH lights are on, your dimmed as well your brights are on at the same time, and for you it just looks like you have brighter light, you DON"T, you just have MORE light, almost the same but in reality it is not, although i have to admid i use this trick in my vehicle sometimes when i think i want to have a better sight in dark.

You have only one lightbulb, you mentioned, but this one contains bright and dimmed light, you actually can many times see both little wires inside the lightbulb, sometimes one side is blackened out to serve the dimmed lights, and you can't really see inside the lightbulb.

Your simple solution, go to a carparts shop, tell them your vehicle make, show them the lightbulb wich was in it, and ask for a better producing lightbulb, inexpensive and can make a big difference.

Just make sure if you buy new bulbs, mostlikely halogen, keep any dirt and even the slightest grease from your fingers OFF the glass, any contamination will shorten the lifespan, especially halogen, but also to a certain degree regular lightbulbs.

Got dirt on it anyway, clean with a cotton rag, slightly wetted with paintthinner, and dry off very good

And yes you can change the setup to 24 volts too, but this is expensive,and you have to be familiar

with the whole concept.

Another source is to get extra lights, but be prepared to dash out 150 to 200 for a set, plus all the expenses and or involved labor costs to install them, to get a set priced at 29,95 or something like that isn't worth your time.

Just go for the better lightbulbs ( for sure to start with )

You mentioned that it gets bright when you mess with the level. So, it's not the bulb, it's the switch that's bad.

just get some halogen bulbs from the parts store. they're pretty cheap and you can install them yourself in 30 seconds.

It seems you may need a new dimmer switch.