Truck Repair: cummins8.3 liter turbo engine, upper radiator hose, vent line

Question
I own a vehicle that has a 1988  cummins8.3 liter turbo engine . I need to know exactly where the thermostat is located, and is there only one thermostat or is there two? If possible maybe you could direct me to a reference that would show a diagram or illustration of the placement of the thermostat. Thanks so much.

Answer
There should be 2 small thermostats.They are located under the upper radiator hose.Might have to take alternator or tensioner loose to remove the housing.There are 4 bolts(2 hold upper radiator hose connection) & a vent line.The water filter is also attached to the thermostat housing.