Just to be clear : You should have 3 lines -> ACC, KL.30 and KL.31
KL.31 (normally black) – should be connected to Ground
KL.30 (normally red) – should be connected to +12V
ACC (normally pink) - should be connected to Ground
Then turn on power, wait for 1-3 secs, press Power Button on our LCN2Kai
Device should come up
If not, can you also see the “current” measurement in your target ?