Optima Alarm XM Infra Red dectectors not working?

Hi,

I re-wired a new optima xm alarm panel replacing existing Optima flush panel. All works except for two infra red detectors. The detectors are fed into Zone two points 3 & 4 and both detectors wired to TA + also both dectors are connected to each other by blue and black wires, red wires are connected to points 3 & 4. Now power seems to be running to detectors. please can anyone advise where I have gone wrong?