Hatefully short joystick wires!
I first hooked up the joystick direction connections to the original joystick wiring harness by piggy-backing 5 new wires onto the backs of the little connectors inside the plug at one end of the wiring harness. This worked very well except for the fact that the original joystick wiring harness is way too short.
So what I ended up doing (and after I did this I realized I could have done it way easier) was to disconnect one end of the wiring harness completely. I eased the metal connectors out from the plastic plug, cut the metal connectors off of the wires, then soldered my own wires to the metal connectors, and plugged the connectors and my new wires back into the plastic plug. This was a painfully slow and tedious process, but it worked perfectly. I ran the loose wire end of my reworked wiring harness to the ChimpSMD.
For the other end of the wiring harness that was connected to the joystick, I left the wires in place and cut the wires down to the right length, tinned the ends, soldered them together with the matching wires from the other wiring harness (connected to the MadCatz PCB), and plugged them into the right places in the ChimpSMD.
What I realized right after I did this really tedious job was that I could have just cut the wiring harness in half, and soldered extra wire to the wires on the MadCatz PCB harness, and only had to solder 5 new wires onto 5 existing wires (to make them longer) rather than cut connectors and resolder them. *sigh* That would have been a heck of a lot easier!
In general, I think that's one thing that I kept learning over and over again on this mod: it's way easier to cut an existing wire and solder a new wire onto it than to rework the end parts of the connections.
Note also the heat-shrink tubing on the 4 wires running from the ChimpSMD to the MadCatz PCB. I used 8 of the wires from the fight stick (replaced by the Remora wiring harnesses), soldered them together and covered the solder points with heat-shrink tubing. I LOVE the way this turned out. I need to buy more heat-shrink tubing!
And one note to the potential viewer here... I made the mistake of not running the 4 USB wires from the ChimpSMD to the MadCatz PCB right away. I was following the ChimpSMD instructions from Toodles and step 2 was to plug the joystick wires into the SMD and test. Well, I did this, but since I was dual-modding, I had the joystick wires running to both boards, but only the ChimpSMD board was powered. When I tested my joystick wiring job, if I had the wiring harness plugged into the MadCatz PCB, the joystick acted as if left and down were stuck on. If I unplugged the wiring harness from the MadCatz PCB, the joystick worked perfectly. The problem here (IIUC) was that the MadCatz was under-powered and interfering with the joystick buttons. HUGE thanks to motoh from #srktt for steering me in the right direction here.
So the lesson to learn here is to follow Toodles' golden rules (from shoryuken.com/forum/index.php?threads/the-official-cthulh...):
Q: What are the golden rules?
A: The two golden rules of dual pcb mods:
1. All pcb's must be common ground.
2. All pcb's must be powered at all times.