We just rewired the basice AIC-18/25 on a E model. The wiring is all pretty much the same. We had a noise issue an the FE control panel. After some long hours of trouble shooting we found that the wire that goes to pin A is really supposed to go to pin R. The 2-13 is wrong for the FE station. The FI shows pin R versus pin A in the 2-13. This cleared up a noise problem and Mic audio problem for us. Good luck,