Started when Nemo popped in to say the step was out. Went round, blipped the blipper and in it popped.. Thought I had just forgotten to lock it and set the alarm. Two days later it is out again ! Started to investigate. Found the step button did not work but turning on the inside entry light operated the step ! Also noticed that when I opened up the van on the remote the external light did not come on. Last night could not sleep for thinking about it................. This morning I went out and went straight to the only thing that I could figure was common to all the issues. That stupid ( with a capital STU !! ) extra control box that is fitted with the Sargent system.. The EM50 Undid it and lifted it out.. As I did it the step started acting like a sodding semaphore flag.. Removed all the plugs and refitted.. Everything started working as it should.. Not having the time or the inclination today I left it at that, but I reckon it was not a bad plug joint but a bad solder joint on the actual board somewhere... I can see I am going to have to remove the unit at some time in the near future, remove the board and go over all the damned solder joints to find it.. One thing is sure about the Sargent system.. It does keep me busy and my interest piqued !