Check that the front indicator is also flashing at double speed at the same time as the rear.

If it is it's probably a fault with the flasher unit , if not it may be a fault with the front flasher assembly or the connection to it.

Fancy lamps at £200-600 per unit to replace when they fail vs conventional at £8-20 depending on manufacturer and powe

Up that to over £1000 if the front led indicator (presumably linked to the DRL) fails on a facelift XF Jaguar, complete headlight unit required, idiocy.

Some lorry rear clusters are knocking on £350 apiece these days (instead of £50 and 50p bulbs), and i dread to think what the pointless possibly small boy impressing fad for scrolling indicators is likely to set one back when they go on, or rather off, the blink.

One more thing i shall avoid for as long as possible.

Barney's £200 units are indeed quite a bargain price, Merc parts are often very reasonably priced but then they ruin things by making parts like bottom ball joints a permanent part of an air strut at some ridiculous 4 figure sum.

Edited by gordonbennet on 07/06/2019 at 21:40