My coolant is full and my T-stat is new. So what gives? I made a small 2 mile trip and back and the dummy temp light went on. The mechanical of course is working and even checked when I got home for the electrical fan to be working and it does. What do I check now or do?

 

When the light's on check the temp at the thermostat housing with an IR thermometer.
if the temps ok suspect the sensor.
If you just changed coolant and/ or thermostat the other suspect is that you need to get the air out of there

 

I did not burp it. I do not have an IR thermometer, would a cheap one from Amazon or Harbor Freight work?

 

If there's air in there and you don't get it out it's going to overheat. Getting it out can take some doing

I have no idea if a harbor fright IR thermometer works, mine is a Fluke. I don't buy anything from Amazon

In any case if there is air in there it probably is actually overheating,; deal with that first before worry about buying a thermometer.

 

What causes it to overheat? Is it just the air as it passes past the T-stat?