Wiper motor control schematic diagram 

Motor Start/Stop Forward/Reverse Control circuit

A - Motor A Fwd/Rev        B - Motor B Fwd/Rev

C - Motor A Activate       D - Motor B Activate

D C B A   Description                          Function
9 8 7 6   PIC16F84 Pinouts   (See program)    

0 1 0 0   Motor A Forward                      Turn about left

0 1 0 1   Motor A Reverse                      Turn about left

1 0 0 0   Motor B Forward                      Turn about right

1 0 1 0   Motor B Reverse                      Turn about right

1 1 0 0   Motors A and B Forward               Forward

1 1 0 1   Motor A Reverse B Forward            Turn anticlockwise

1 1 1 0   Motor A Forward B Reverse            Turn clockwise

1 1 1 1   Motors A and B Reverse               Reverse