After being unsuccessful in fixing my problem in this post (https://ogrforum.ogaugerr.com/...ght-bracket-polarity), I came to the conclusion that my board in my 30-1164-1 Mikado was defective. The board is/was a 3v board, swapped after the original 5v board died. Nothing connected to the 8 pin harness would light up.
I decided to swap the board with an engine (3v PS2 diesel, 30-2381-1) that does not use an 8 pin lighting harness and simply change the sound files, in the hope the diesel's board would allow the 8 pin lighting harness to work and my Mikado's marker lights would work again.
I painstakingly swapped the connector shells (the Mikado has 5v connectors), and carefully reassembled everything. The good news, the marker bulb now works! The bad news, it wont respond to the LMK softkey on the remote. I verified the pin was correct (pin #3 on the 8 pin harness, ditch connector 1) for the marker bulb, and verified the sound file had the key set to marker on ditch using ADPCM player. Still nothing.
I also tried a PS2 diesel file with ditch lights, and the light flashes as if it were a ditch light, so I'm pretty sure I got the pinout correct. I've also checked the wiring countless times and reset the engine/reloaded the sound file and still cannot get the LMK softkey to respond. It just constantly stays on. This isn't a huge issue, and I can definitely live with it, but I would prefer to have the softkey work if possible. Is there anything I may be missing? I can include pictures if needed.