</font><blockquote><font class="small">Quoting brisvr4:</font><hr />
The sensor from the bottom of the radiator is the for the fan. It will work fine in the thermostat housing.
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This is sort of true. That switch kicks on around 175°F. I'm not sure when it shuts off, because on a running car, the temp almost never gets that low at the water neck. It's fine in the bottom of the radiator, because the water DOES cool off well below 175 before it re-enters the engine. It simply does not work well on the water neck.
I'd suggest you get an inline water temp adapter like i'm going to. Otherwise the fan will either basically run non stop as soon you as approach operating temp, or you'll be running off the A/C switch which kicks on when things start getting pretty damn hot.