my right headlight has been permanatly out. i had problems, it would click on, then off, or would randomly begin to work while driving, now it doesnt go on at all, neither does the yellow top marker

i dont know anything about electrical, i changed all the fuses, and all the plugs are still connected.

what to do?

is this an aftermarket plug and play kit?

yes. 04 wrx.

bad wiring maybe, cheap kit, combination of the two?

Sounds like your ballast went bad.

how do i check or fix a ballast?

that happened to me too good thing i was at my grandma's house just gonna pull out from her drive way and all the sudden my left hid went out. i quickly diagnosed the problem and found out that my the neg plug was loose. so double check your wiring. check for loose cables and if it does not work then i dont know

bad ballasts do that.

ballast for sure get replacement

use the good side to switch to the bad side to diagnose if it is the ballast/ ignitor assembly or hid capsule. everyone is jumping to conclusions without a proper diagnostic of the problem. bad ballasts and capsules show the same problem. if your capsule looks all black inside, this will happen as well.

its not that i'm jumping to conclusions.. i have to luxury of sending back ballasts and using new ones... on the spot. that and i've noticed that 85% of the time it is the ballast

the best and right way is still to diagnose instead of assuming. its not too hard to plug them in back and forth or use a multimeter to determine what the problem is. a damaged capsule will eventually damage the ballast because of higher current requirements