So just did a tune up, swapped spark plugs and went with magnecor wires recommended by mazdatrix because they look cool. After starting up again engine never reached warm temp. The odds my thermostat broke at the same time are slim, so I replaced it. Nothing. Is there some electrical damage that can occur that may have broken the sensor? I'm not seeing the correlation. Anyone have issues with the temp sensor? I doubt its broken as it shows a bump when I turn the car on and off.

 

Have you checked the one wire connection at the sending unit?
It may have been dislodged when you did the plugs/wires.

The "bump" you're seeing only tells you the gauge is getting voltage.
The sensor is a variable ground and it doesn't appear you're connected.
If the loose wire was grounding on anything else, the gauge would read full hot.

 

The only wire would be the one that taps into the radiator with the sensor right? Did the check per the FSM and its good. So odd. I was messing around under the engine by the oil temp sensor...

 

There is no temp sensor for the oil but only for pressure and the level of oil. The gauge temp sensor is next to the oil pressure sender and has but one wire and it should be Yellow/White.

 

Did you check the connection just forward/below of the oil filter. There are two connections there. One for oil pressure and one for the water temp. The one sensor on top the radiator is the low water sensor.

 

That's gotta be it, thanks guys. Totally thought that radiator probe had a dual purpose of level and temp :/