I'm trying to run a few things off the 12v connector inside to the right of the coin door, including lighted flipper buttons and undercabinet lighting. If I hook them both up individually, no splitter, they work fine, but when I try to run them off a splitter, only the lighted flipper buttons work.

The splitter itself is not the issue I don't think as it works in other games, including both my LOTR and tspp.

The connections are all good, checked with continuity.

Sterns connector has three wires, black (grnd), gray-rd (12v) and red (5v I believe).

In my splitter (ignore the heat shrink, I was moving things around) red connects to stern's gry-rd wire and black to black. My splitter has a 3 pin connector to stern's 3 pin connector, but then I split them into 2 pin connectors as 5v isn't used.

Anyone have any thoughts why I can't get both the undercabinet lighting and the flipper buttons to work at the same time?

Coin door connector:
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My splitter:
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My splitters connection to coin door connector.

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I have continuity from the first connection to each branch. The splitter works in other games.