Galaxy Tim

Hi All, I hope you can help me as I’ve tried all I can think of and not able to get rid of Aux Tamp error to exit engineering mode of Galaxy Flex 20. ~ I have two Deltabell external sounders and want to wire both into the Flex 20. I’ve an internal speaker too. ~ The Deltabells bells are wired into OP1 and strobes into OP2. OP3 has been used for internal speaker which I’ve not bothered wiring tamper circuit for. The +12v for deltabells is coming from the left side of the board. The 0v is wired into the 0v terminal to the right of the three OP terminals. The deltabells have two tamper terminals which I have wired and brought back to the board on yellow and green. Yellow is wired into the T beside the OP terminals. Other tamper terminal from deltabell is wired into 0v. What am I doing wrong? thanks Tim