This problem becomes not one problem related just to brakes. One by one it will multiply. Check any fuses but I do not think it is a fuse or a relay issue. You should also try to activate your cruise control and I bet you you will get a blinking SET light and a cruise that does not activate.
Go under the steering wheel and trace up to the top of the brake pedal. There are 2 switches attached to these pedals.One has a Brown color housing and the other black. Twist the black switch counter clock wise slightly until you feel it loose and pull out gently. Do not force either of these switches and gently undo the wire connections to it. Take the black color one out of the vehicle and do a surgery on it. you will need a small screwdriver and carefully pry open the switch. There are two brass contact stems inside. Take each of them out and rub on a fine sand paper until the black burnt like color is gone. replace them the way they were before and put the switch back together. This takes only 5-10 mins. If you do not want to go through this cleaning, purchase a new switch please. Replace the switch back and immediately, your brake lights, cruise control and everything else related will begin to work. Black switch is Stop light switch. Brown one is Cruise control switch. Dealer repair is about $250 at least. This is very easy and you will feel on top of the world! try it. If you screw up the switch, buy a new one as you did not screw up the van.