does any one know if there is a separate fuse for trailer side lights or do they work of the unit ones ? can’t find one on fuses box lid.
Have you tried the red 10 amp ones, 2 together on a red background square marked ‘max 10 amp’? Mine sometimes blows 1 of these when picking up a faulty trl and they do affect unit side lights.
yes have checked them, 1 & 2 , had trailer socket tested, only 1 feed to trailer
LED sidelights on the trailer? Could be a loose wire.
They run them in sequence rather than off a main spur, so 1 broken wire = no sidelights on that side 
turned out to be socket on back of cab. This comes pre-wired with about 1mtr of wire, on the other end is a square socket behind batteries, that was fubar inside. Not bad, it’s lasted 2yrs 2mths 10 days from new.