OK a little update, apart from some teething problems I can now confirm that Dave's PWM controller works great with my dashboard fan speed indicators.
Between Dave and Alec a member of the electronics forum, they have given me exactly what I want, my dashboard not even needing to be removed to complete everything.
It will be another few weeks before all is installed permanently in the Land Cruiser and proper testing commences. The real test though will be climbing Spain's mountainous desert areas fully loaded in August, temperatures are normally circa 50°C (122°F) during this period, a test indeed!
