12 Pin trailer plug - keeping it secure

Never had a prob myself, but if you're worried, instead of a rubber band...use a bigger rubber band !!.....cut off say 100mm from a motor bike tube ( probably a small one like a postie bike ) and slip that over it ..

My old flat 7 pin had a latch on it that hooked the plug and socket together, don't they all have that?

I have been using a flat 7 pin socket/plug combination for years without any problem.

The spring loaded cover includes a couple of lugs that when opened and the plug inserted, provides a mechanical locking arrangement.

Actually, I lie!
Have had the plug exit the socket on one occasion when I hit a washout and smashed the socket to bits.
It's in a bugger of a location and I just have never got around to moving it:-)

Never had the problem myself either but if your worried why not use
a reuseable cable tie?

The flat 12 pin unit should be kept in place by the spring loaded lid. If it doesnt you have a faulty unit. The flat 7 pin is the same.

Similar response to others above. We have never had an issue with our metal pair. The spring loaded lid on the socket sits over some extrusions on the plug.

I also keep it clean by hosing it with a strong jet, even when not used. Maybe dust is the lid hinge or spring is the problem.

This is a very similar pair on ebay (Item#: 321519121469):

I too, have never had a problem with the 12 pin flat plug. BUT mine has a cover on the plug that is hinged to it opens horizontally and will go down the side of the socket and lock on to the socket. It also has the cover to the socket which is hinged and opens vertically. This then locks on to the top of the plug and holds that in place as well. The only problem that I have had is with the rubber boot on the plug not being long enough or flexible enough to allow the wires to manouvre. This was fixed by the used of silicone tape. The new WONDER-HELPER to all travelers.