If you mean cooling system thermostat, it is at the end of the lower radiator hose at the engine side. You will have to remove the hose at the engine end to see it.
Plugged radiator Water pump Bad thermostat
You can find a fuel line diagram for a 1988 Chevy Cheyenne in the vehicle's owner's manual. You can also find it at various auto stores.
Remove the water supply hose from your 1988 Chevy Cavalier thermostat housing. Remove the thermostat housing bolts. Lift the old thermostat out and drop in the new thermostat.
If a 1988 Chevy Cheyenne dies when it is put into gear, check the fuel pump. If the fuel pump is not getting adequate fuel, it will cause the car to die.
worth keeping it
It goes up.
The drivers side is the odd side, #1 is in front.
Drain the water from your 1988 Chevy Corvette cooling system. Remove the water supply hose from the top of your thermostat housing. Remove the thermostat housing bolts. Remove the thermostat. Reverse the process to install the new thermostat.
I have the same truck and it's 26 gal.
connected to thermostat housing
You will often find a diagram of the fuse box for the 1988 Chevy Cheyenne in inside cover for the fuse box. This fuse box is located on the driver's side of the vehicle under the dash. The cigarette lighter fuse is generally marked as ACC.
To locate the thermostat on a Chevy Celebrity follow the upper radiator hose to the coolant outlet, which is mounted to the top of the thermostat housing.