i have fitted a towbar to my l322 and when i plug the lights in for my caravan they pulse on and off? this then stores a a fault code?
when i turn it onto side lights they stop flashing?
has anyone had this problem ?

Which lights flash on and off? All of them?? I don't know how similar the l322 is to the
P38, but on the P38 the BECM monitors current levels, so, for instance, if you wire both sets of side lights for the caravan connector to one side light wire in the P38, you will get a fault. Construction and use regulations require separate feeds for left and right side lights and the BECM will recognise the fault if this is not done.

Tell us which lights flash and you may get better info.

thanks for the reply , the side lights are the ones flashing?
i used the range rover wiring kit that came with the towbar this is a land rover part?
i have been told that it could be because the lights on the van are led's not standard bulbs ? could this be the reason?

Minimum load is 5 watts per side I think for side lights on a trailer. Are all the lights on the van LED? if so the load may be too low. Try a trailer board if you can borrow one or change the LED bulbs for normal and try again. I did not know that LED rear lights were homologated. Most of the ads for LED replacements say not legal for road use. Otherwise you may have a wiring fault like a bad earth.