Ok ... looking at your image (and this is off the top of my head so be warned), get rid of the cap between pins 2 & 10, remove connection between 3 & 9 (just leave them dead pins unless you have a reason to short them), remove resistor on powerline and run 1 12v line to pins 7 & 8 they can share the power line, if you are controlling this with arduino set pin 5 to HIGH and 6 to LOW and reverse that for spinning the other direction. I don't? have any resistors or caps in my setup with lb1641 ... and get rid of the diode? on pin 4.