Explorer Heater Bypass Valve
With a little creative vacuum-line routing, this valve is easy to retrofit to any vehicle not originally equipped, so as to keep heat out of the cab, and out of the A/C airstream during summer, while still allowing full coolant flow past the temperature sender & the ECT. Set it up so that without vacuum applied, coolant flow is normal; and with vacuum (spliced into the white recirculate door line), it's in bypass.
