boot

Have you checked fuse? Not sure if dash light would light if that needed replacing though. Have you wired the the right way round? My limited knowledge of these things, is that if a standard bulb is wired with polarity the wrong way they will still light, however many led units won't.

Also, not sure on having to have them all changed to get them working (might do) but chances are you'll have to buy a LED flasher relay. You can do it with resistors, but the LED flasher relay is less likely to be problematic, both now and in the future.