Where is the thermostat located on a 1990 Ford Econoline Van?

the thermostat is dirctly behind the serpentine belt mounted to the engine block Follow the upper radiator hose to the water outlet (metal and bolted on) undo the bolts and the little metal thingy inside is the thermostat. Clean off the surfaces very well but be careful not to gouge the metal apply a thin coat of rtv sealant set the thermostat in the outline in the water outlet( the part you have in your hand)apply another thin coat of rtv sealant then the gasket then another thin coat of rtv sealant (I stress THIN COATS) other wise the thermostat will slip off center and the water outlet will break when you tighten it down. Tighten the bolts down evenly. the end