I recently bought an EF falcon but i cant lock, it locks the doors then unlockes itself straight away and beeps the horn.... now ive checked the interior light is ok. Ive pulled the trims off all doors they all go up and down. so i tried disconnecting each motor one by one doesnt change a thing should i just start changing motors and the BCM can anyone point me in the right direction??????

Check the open/close buttons I dare say one is stuffed or sticky, The missus EL does this...

All doors are shut. doors lock and then unlock horn beeps, do it again and it locks proper. and sometimes it beeps but locks... I can't be bothered locking for the fault as it does it once in a blue moon but it is relatd to the buttons.