Caravan towing electrical problem

Hope that someone can advise on this please (that's if I can explain it!).  Arrived back from trip to the Lakes a couple of days ago.  The caravan performed absolutely fine.  I hooked up the unit (Bailey Ranger 500/5 2004)  yesterday evening and set off to take it to store.  We went a short distance and the offside indicator stopped flashing.  I returned home and took a look at the grey and black connectors.   The grey one was wired as follows: 1 yellow, 2 not used, 3 white, 4 green, 5 not used, 6 red and 7 black.  I cleaned it up and reconnected the wires.  I then noticed that by pushing the cable to the black connector the indicator started working.  I opened up the plug and two of the wires had apparently become disconnected.  The ones that were still connected were as follows: 1 yellow, 3 white, 6 red, 7 black and brown combined.  This left 2 which looked as though it had had the green cable to it and blue into either 4 or 5.  Little of this looked like the wiring diagram in the unit's manual.  I cleaned the plug again and re connected the obvious wires.  I then tried green into 2 and blue into 5 - no joy.  I changed blue into 4 - this seemed to work.  I drove to the storage site and on the way noticed the cars fog light indicator was on, even thoough the switch was off.  On arrival I disconnected the black plug and the fog lamp indicator went off.  Having looked at the club site this morning I see that there is a section on wiring the plugs. Again, little of the wiring on the club site looks like the wiring on my caravan. Is it simply a case of stripping out the wires and rewiring them as appropriate for the year of the caravan or is there something going on beyong this approach?  Also, it seems to me that part of the problem why these wires have come loose is that they are stranded wires and tightening up the screws damages them, leading to failure.  Should they be ferruled to try and avoid this problem?

Thanks John.