Where is the thermostat located on a 1990 Nissan Sentra?

I believe it is on the left hand side of the engine, on the firewall side. It is soewhat difficult to get to. You need small hands and patience. This is alwo where the thermostat is located (3 bolts). I believe there is an answer on this site for the thermostat and the sensor is adjacent to it. I considered changing the thermostat, but since it's somehwat complicated, I will leave it to a garage to do it for me.