for what it's worth, i swapped in an electric fan to my Volvo 240. Grabbed a fan and relay from a Volvo 850, trimmed the shroud to fit the radiator, one lead went to the battery, another to ground and one lead to my fan switch, which fits right into the radiator...setup from Volvo 740...when the coolant gets to a certain temp, I believe 87* celcius, it kicks the fan on and shuts it off when it gets below X*. It works flawlessly and got me to Colorado and home without the slightest problem. For the Z car, I have an in-line fan switch housing from a Saab, which is to be mounted in line with the lower radiator hose...just interested on what temp fan switch to get.
