Hi edge01, thanks a lot for replying and the offer of help. REALLY appreciate it. But I have just solved it.
I found the following thread on the web.
http://www.pradopoint.com/showthread.php?22535-Trailer-Indicators-Fuse
I found another couple like it too. They seem to point to a special fuse for trailer indicators if the trailer socket was factory fitted. Weird. The engine bay fuse box picture the guy shows is a different model to mine but I found a fuse in an unlabelled slot and it was blown. Odd thing is I swapped out my radio fuse into that slot and retested last night and it didn't work.
This morning I got to repco and got some fuses and replaced the unknown blown fuse while leaving the radio fuse in. I pulled every fuse and checked it, Retested and it worked!! Doesn't make sense. I could pull that fuse and see if it stops but right now, I ain't touching a thing

But when I'm back from holidays I'll check. I'd like to know what's going on.
Thanks again.