300s already have relays so look at your connectors to make sure they aren't burned, put some quality lamps in there like Osram Nightbreaker, and fitting brand new lenses makes the world of difference, believe me.
Otherwise, you need MOAR lights
Cheers
Oh no they don'tno relays in the 300 lighting other than the one used for the dim-dip function.
The multi contact lighting switch takes care of it all.