There's 2 sensors, I'm assuming one for gauge and one for ecu. Which of the 2 is for the gauge? 2.2 non vtec. One sensor is on the thermostat housing, other is off the upper hose on a housing bolted to the head. Bought a new sensor and can't tell which one is which. Pin connectors look identical

 

There are 2 ECT sensors, one is a single wire and the other is a 2 wire connector. Both are screwed into the cylinder head located under the distributor. The ECT sensor for the gauge cluster is the one with the single wire.

The two switches that you are referring to are the A & B coolant temperature switches. They send signals to the radiator fan control module not the gauge cluster.

 

OP, what's your goal ? If you're trying to replace the fan switch, then you should be replacing the one at the thermostat housing which is located towards the back of the engine on the passenger side..following the lower radiator hose. Normally most parts stores don't stock the other sensor at the water outlet at the top radiator hose as it's normally never replaced. You would need to either get that from the junkyard or the dealer. Again, this rarely ever gets replaced. But the fan switch gets replaced all the time. This is the one that controls the fans during driving conditions.

 

And the front ECT on the upper radiator neck controls the condensor fan.

 

The gauge in the car is inaccurate. Right now it's staying 1/4 of the way up constantly. Sometimes it will shoot up all the way to hot, even if I just start the car.
I ordered the sensor from Carquest and told them I needed the one for the gauge and they sent a 2 wire sensor. Must be the wrong one. I looked at the single wire sensor on the head. Soaked with oil and some of the harness is exposed. Gonna grab a sensor from the junkyard and splice in a new section of harness

 

Like Ghost already said, the single wire plug under the distributor goes to the dash and gives you the readings on the coolant temp and is called the "coolant temperature sender". The two wire plug next to it is for the ecu. This one is called the "coolant temperature sensor"...the one on the thermostat housing that controls the fans is the "fan switch" at parts stores.