Ok I think I know a solution.
I am going to get wasted spark before the end of the year.
I will get the uprated fan loom kit at the same time.
I do have a magnificient new engine bay loom by MSD.
I just read the add and the cooling wiring loom was a optional extra.
My bad I will just get the lot done.
Its only if I sit with the engine ticking over for say 10 mins there is a overheating problem.
once I get going she self cools.
Still wouldn't mind swapping over the relay until then.
On one of the pictures in Haynes it goes on about a fusable link but I have a positive to the switch so it is a relay issue.
Don't think its burn't out as the wires were big 30 amp stuff.
It'll be a relay just need the right person to read this as I'm sure anyeone who's had a cosworth will have chased this problem.