hoping someone can help i brought a new bailey last week and soon as i plugged my car into the van my rear light blew a fuse in my fuse box (cars) i replaced the fuse and plugged it in again and it blew straight away , puzzled the lights are not coming on in the van but the indicators and the brake and reverse lights work any ideas please i have checked the plugs all seams ok the plug on the van is a bit old but all looks ok
Depending on the year of caravan, there should be a rocker switch in the caravan with 3 positions, the centre being neutral, one way should indicate 'CAR' and the opposite way 'CARAVAN'. Have a look to see where this is positioned as it should be in the central position when connecting up the 12N plug to the car so no electrical current is live otherwise if you connect up the plug with a live feed it can cause a spark which in turn will protect the electrical circuit by blowing a fuse which sounds very much like what could be happenning. Once the plug is connected then switch the rocker switch to 'CAR' which will provide the feed to the internal lights. As the rear lights on the caravan are not affected, the problem has to be related to the 12 volt circuit in the caravan that is connected to the leisure battery circuit.
As birdman says there is a short.I would strip the wires to the caravan plug back then fit a new plug.If that fails take out the bulbs on the caravan lights that are affected and put them back one by one.With one of my vans there was a short in the bulb holder with rust and a connection was touching the other.
Also check car socket with another trailer or light board to eliminate that before taking caravan wiring to pieces. If car is ok then dismantle caravan 12n plug & go from there.
The short is likely to be at either end of the wire. After checking the plug check where the wires come though the rear panel. There are often sharp edges which will cut through the insulation