Could you please (1)post a pic of the external relay cover so I can get the exact same one. (2) please show pic of wire connections to back of external relay so I can get feed polarity right.(3)pic shows connections to back of circuit board. Did you leave defunct relay attached in front. Solder joints would infer yes but just want to be sure. Also, the solid silicon diode you referred to in your schematic is a 1N4007. This little baby is what can cause the no crank condition when battery and others are known good. 0.7 v DC drop from 12 v supply across diode is the result based upon manufacturing specs. Also the Blue Gray Black Black Brown resistors on the front of board are 68 ohm resistors just for extra info for the follow forum users