Modern car and old caravan electrics

I'd suggest there's a fault some where in the caravan's electrics especially as the caravan's indicators are just staying on & not flashing. Your X5 is rapidly flashing the indicators because it thinks there's a failed indicator somewhere. Try a simple trailer board and see what happens. Faults with LEDs tend to be the other way round ie LEDs on the trailer because they don't draw enough current for the tow car to 'see' them.

May even be a dodgy bulb on the caravan. I would start by removing the bulbs from the caravan, connect the car, test the caravan light fittings with a multimeter. The negatives need checking too.

Thanks for the advice guys I do see what your saying but the caravan worked fine on my 5 series 2015 and now it’s not when connected to my X5 2019 also if I plug my bike rack into my X5 it’s fine but that does have a 13 pin plug 

There is an adaptor between the caravan and the car, and not all adaptors are the same because of the way they connect the earths. Start with what happens if you fit the adaptor WITHOUT the caravan, and if you can, try your caravan and adaptor on another 13-pin vehicle.  This will start to break down the possibiities for where a fault may lie.

A tester for trailer lights is a cheap purchase from internet, or you may be able to borrow one from another caravanner or a garage.  They test both car and caravan electrics for road lighting circuits.

curious ??? 🤔 

We also have an old caravan (2008) and  a modern towcar, with LED lights (VW 2016).   The car has 13 pin electrics, so does the caravan, I fitted that myself  when the van was new.

We have not had any problems with the lights at all, only a problem with the so called " smart alternator" not charging the battery sufficiently, but that has now been solved.

The first thing I would check is the adaptor, which I assume you are using to connect the 2x7 to the 13 pin system?    IMO, you would be better to rewire the van with a 13 pin plug, fewer connections to go wrong then.

Thanks for all the advice everyone I finally got to the bottom of it and it was a wire that was at times touching another wire obviously my new car must be more sensitive to this type of issue than the previous car it wasn’t an issue there. Very thankful it wasn’t an issue between old caravan and new ish car though