Driving along towing a trailer, indicating and then all the lights just stopped working, even break lights, also noticed the gauges stopped working and none of the warning lights come on when starting or glow plug lights check lights etc. Car still starts and runs fine. Any ideas at all? all the fuses are fine, bulbs fine. Could it be a MAXI fuse?

sorted. re checked the fuses, this time with glasses on and found three blown. But why did this happen in the first place? watch this space for the next exciting episode.

Check the reverse light cable

Ours blew the Speedo + lights fuse when it frayed on... something, could have been the A/C unit. Can't remember what the AA man said. But yeah, that cable.

Sounds like a short on the trailerboard. Need to be careful with these sorts of things - I popped my airbag ECU due to not having a relay between the trailer and the car. Had all the symptoms that you have - lights and dashboard not functioning.