93 celica electrical

[OffRoadDude]

Hey everybody.
My friend recently bought a 93 celica GT. Nice car, but it has some electrical problems. I already tore out an alarm system that wasnt doing anything. I replaced spark plugs and wires btw. The car runs good, now, but when he steps on the brake, the right taillight goes out and the front driving/turn light comes on. Anybody know what this could be?
its pretty late and i should be in bed haha. thanks in advance

Edit: also, when he turns on his right directional, and steps on the brake, the directional flasher flashes like crazy.