Hey guys I've had this problem with my truck(2002 Dodge 2500 4x4 Cummins) so every time i turn on my lights the passenger side light is super dim i mean theirs like 20 percent light compared to the other side and im just wondering what could this be i was thinking it has to be a ground and if so where are the grounds located for the headlights thanks.

Bulb perhaps? have you tried swapping bulbs from side to side?If not that, perhaps water or dirt in the headlight body?

Headlight fuse is most likely blown too.

also if it helps my high beam indicator is always on now

Sounds like you have a burnt out light bulb and a filament has shorted across the bulb internally. The ground for your low beam just MAY be going through the high beam circuit causing the indicator to stay on. If you replace one bulb the other is probably due for replacement also. Just make sure you don't touch the glass on the replacements.

Tom