3, 4 player issues

[ArcadeMan203]

I have the 6 slot jamma board in my Simpsons arcade and have ran into a issue where all the 3rd and 4th player controls are stuck in the closed position.
I can not get player 3 and 4 to work. It looks like someone that had the system before me created their own harness for 3 and 4.

Thinking of buying a new kick harness and rewire 3rd and 4th player controls but I am very new to wiring and such.

Sorry for the bad cell pics

 

[ArcadeMan203]

here is a pic when going into test mode for the Simpsons. As you can see the controls show constant contact

 

[JoeAwesome]

Rewiring might not be a bad idea, but what happens when you try the board straight to the JAMMA harness in the cab, and not the 6 slot switcher?

 

[ArcadeMan203]

it works except player 3 and 4 when attached dont work. I dont think its the jamma board as player 1 and 2 work fine since they run through the board. It's only player 3 and 4 that are giving me a issue.

I should mention I have tmnt, avengers, and sunset riders which all have the same issue when plugged in making me lean more towards a wiring issue with the 3rd and 4th player.

 

[JoeAwesome]

Compare the wiring for the harnesses with info here.

 

[ArcadeMan203]

think I figured it out....dont think the original owner added diodes to the kick harness which when all the games are plugged in gives a false reading to the arcade making it think all the buttons on the kick are being pressed. I'm going to take out the harnest and try to add some diodes