Elsewhere I have posted a request for assistance in identifying wires from a van to the correct pin numbers when fitting a new plug to the caravan.
When I started fitting the new 12-pin plug to the caravan wires I noticed that the flat sides of the plug were interchangeable, although being slightly different. Where the sides went over the pins the surface was raised to clear the wires. On one side the raised part had a 45-degree slope, while the other side had a 90-degree ridge.
That meant that the lip on the spring-loaded flap on the vehicle mounted socket was meant to drop over the 90-dgree ridge and lock the plug firmly in place.
However, in my case whoever had fitted the plug onto the caravan wires - maybe even in the Jayco factory! - had fitted the cover with the slope on the top. That meant that the flap would not hold the plug securely - as I found out when it dislodged.
Despite making 28 trips in the Sterling covering 21,524kms I never noticed the difference between top and bottom of the plugs. That is until after the plug fell out and I had to fit the new one.
Might be an idea the next time you are getting ready to roll to have a look at the plug and make sure the 90-degree ridge is on top for the spring flap to lock the plug on securely.
(It is a simple matter to reverse the top and bottom plug sides - two screws each side and the wires are not disturbed.)
It is not always that the mistakes are by unskilled workers.
Once, I found a similar problem as Long Weekend's after I returned home with the van from an autoelectrician's repair. He had traced and repaired a fault with the warnings lights for the van's sway control. I will go him again with return work.
Both sides of that 12 plug fitting are quite similar and I suspect, it is easy to make a mistake with it, if rushing to finish a job.
For me, I noticed the fitting was upside down when I was unhitching and unplugging, after returning home from the workshop. So only about 5km, not 21+k km
