8004 pwm to dim leds

hello everyone i just bought the 8004 pwm. not quite sure how to hook it up,i am trying to use it to dim my led taillight retro fit. i have four bread boards filled with leds. each board has a neg and pos how do i intergrate that into my cars tailights so i can dim the leds wen the the lights are on and the leds to full power when the brake lights are on, do i need something else to do this thanks

No need for K8004.
This circuit can be wired with a couple of resistors and diodes.

thanks for repling but i wanted to go with the pulse width modulator is it possible ive seen other people do it with a pwm but not a velleman is there anyway you cud draw a schematic