91 K5 silverado

okay lets start with the fuse

the power window fuse keeps blowing, it used to work until one day it started to go off after i replace the damn fuse 3 times.
should i just get a manual window with a new door. from junk yard. or this problem fixable.

AC

no condenser, when i turn it on it blows weak air whether the fan is on 1,2,3, the heat comes from the engine.

the blinker is blinking fast on either turn, the light bulbs are fine too but they blink fast. the hazards are solid no blinking