When I put my foot on the brake the dash light dims and the front dip lights come on I have replaced the switch on the top of the brake pedal but no good.
sounds like bad earth/connection on brake light holder/board. check all connections on brake light bulb holders ,including bulb itself make sure that loom connector to light unit/board is clean and good connection ,also check earth point on body[follow earth from lamp back to find earth point.]ensure correct bulb is fitted.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.