96 Mazda Protege coolant temp sensor

How difficult is it to change the coolant temp sensor on a 96 protege? I think I need to change the sensor and the thermostat.

Depending on the symptoms you probably need to change the temp sender OR the T-stat.

Whats the temp gauge doing?

This is usually pretty easy because the temperature sensor is generally right below the thermostat housing. Check with various Mazda forums on the Web.

Which one? There’s one for the gauge/light. one for the computer, and one for the radiator cooling fan.


The temp gauge has been going up past the normal position then drops back down.

I am not sure. Based on the temp gauge going up and and down, it may bo for the cooling fan. I suspect it is not running.

The fan should run non stop with the AC on. Does it & does the temp gauge settle down?

I think these use a low & high speed fan circuit. Maybe low speed is’nt kicking on when it should.

Got wiring diagrams?

The AC is not on. The temp gauge does not go up that much in stop and go traffic. It seems to go up more when i am braking or going down hill, if that makes any sense.

You missed my point about running the AC to see if the fan works. But since it does’nt overheat in stop & go the fan is apparently working as it should.

Try this very simple little test.

When the engine is warmed up mark the level of the coolant in the overflow bottle.

Wait 2 hours & check it again.

If the level has’nt dropped theres a leak & air in the cooling system.

I just replaced the coolant temp sensorS on my 96 Protege, and I wanted to capture the facts for the next person. There are TWO sensors. To access either sensor you must completely remove the air filter box.

If you’re standing in front of the car looking at the Distributor, there’s a sensor beneath the Distributor, with a single spade tip wire coming out the front. That sensor controls the temp gauge on the dash. It can be removed with a 12mm DEEP socket.

If you’re standing on the driver’s side, look below the Distributor to the right (toward the cabin). There’s a sensor there with a two wire plastic connection. This sensor sends signals to the PCM (Powertrain Control Module). I believe this is the sensor that controls the fan (but I’m not positive). It requires a 19mm DEEP socket.

The hardest part of replacing either one is removing the wire. With a deep socket, they are easy to access and remove.