Hey Phil,

The 940s and later 700s got electric cooling fans attached to the back of the rad. Even flat out they shouldn't be able to noticeably cool an engine if the thermostat is properly closed based on upper block coolant temp. Initially these were single speed fans controlled by a thermostat inserted into to the upper right corner of the rad connected to a fan relay under the hood. For LH 2.4 these became a two speed fan with the relay being controlled by both the ECU (based on the block temp sensor reading) as well as a pressostat on the lower A/C condenser rail. I think with effort a few have been able to retrofit the 740 electric fans to a 240, the main issue being a temp sensor if you don't want it running full time.

Note for LH 2.4 owners reading here, many of the later rads (ike Nissens) are universal fit and have a thermostat hole in the upper right corner. They come with a rubber grommet and plastic plug for it (check if it's hidden underneath). Many (including me now) recommend using a couple of black UV-proof zip ties around the plastic side tank so it can't blow out, but please realize the over-pressure weak point in the cooling system then becomes the heater valve and heater core, which are even more fun to deal with.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now