Please tell whether your 850's radiator fan runs on low speed continuously - or if it comes only when the block starts to get too warm. I know you can't tell from the driver's seat - it's far too quiet for that. Even on high speed, I find you can't hear it when driving.

Is this fan is programmed to run continuously on low speed?

I converted my '89 245 to an electric radiator fan using one out of a '93 964.
(I'm told it's the same fan as the 850.) I've got the fan, the shroud (modified to fit my smaller radiator) and the original relay, with complete wire harness. I'm using temp switches in the lower radiator hose, have also tried them in the upper hose.

I've had a devil of a time tweaking it up to run perfectly without intervention from me. At stop lights, the temp gauge needle rises about 1/8" or more - this is after installing a new lower-temp switch (on at 82ºC, off at 77ºC) into the lower rad. hose. My thermostat is 92ºC.

I've wired it up a few different ways, with various temp switches in the upper and lower rad hoses, always with a manual switch to the driver's area and an indicator to let me know when it's come on via the temp switches. Still can't let it run without my help, and I'm getting frustrated.

Thanks!
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[aka Sophie's Maintainer] Sven: '89 245, IPD sways, E-fan conversion, 28+ mpg - auto tranny. 850 mi/week commute.