Slow blinking coolant light diagnosis

[runjmc2]

It's getting hit here in AZ and on my way home today I had a slow flashing coolant light. I just cleaned the radiators and the car was running at a reasonable temp, around the middle. After quick research it is likely engine compartment overheat or low coolant. It has not cooled down enough to check the level and I suspect it's the engine compartment temperature that is causing the light. For the first time ever, after the car was off and the key was out the engine compartment fan kicked on and I could feel air coming out of the passenger side vent. The air was of low volume and not very hot. I have a dura metric.

Looking for additional insight into how this system works, troubleshooting and possible repairs. To date I have done all my own repairs. More specifically is there a temp sensor that could be bad? Since the fan is working, are there more than one or is blockage a possible cause. Any insight from those that have gone down this path much appreciated. With the durametric I'm assuming I should be able the manually turn on the fan. Are there other test? Thanks