As I say MSD "Uprated" switch brings the fans on earlier, around 90 degrees seems to ring a bell.

I doubt there is a particular switch one for a RST, the cars were never designed properly in the first place (although it's probably not an issue on a standard example) in any case they were built from the parts bin.

It's just the same story with the Cosworth, the standard switch is useless (This is the complete opposite to RST, fans come on to early then stay on for an eternity) it's the same item as found in a MK2 Fiesta!

Martin