I've done an electric fan conversion on the missus's Disco 300tdi, the switch I used had two positions, 82° and 88°, setup for dual fans. I've got to say in that vehicle it ran OK on the 82° trigger point switch, but it runs signifigantly happier on the 88° settingI'm about to embark on the thermostat mod for my TD4 auto. There is a fair bit of info on here about it but I'm wondering about a definitive discussion/summary of the pros and cons of the two different temp options that seem to be most widely used.
Is the 83° or 89° preferred?