I've been thinking about how to control the thermofan on the trans cooler and, at the same time knowing I wanted some extra gauges to keep an eye on things decided to go with a couple of these...
Auto Meter
They're a bit over $200ea but they can do much more than ordinary gauges which will cost well over $100ea but can't do anything else.
I got a trans temp gauge and an Oil pressure gauge.
So I'll be able to control the fan and it will also change colour and flash the change in colour to warn of exceeded limits, they have memory recall and a 0-5v data logger output.
I looked at some other similar gauges and whilst some were cheaper they didn't have all of the features including, most importantly the output driver.