1KR-FE fan is acting up

[tamrat]

So yesterday, my 2009 Yaris overheated. The coolant temperature warning light came on and I parked on the side of the road to cool it a bit. While parked I noticed the fan wasn't running. And I remember having the AC on. After it cooled down, I cranked up the heaters, rolled down the windows and got home safely (warning light never came on).

Upon further inspection at home, I noticed that the fan rarely come on. If it does, its on the low speed mode. I'm assuming the fan is good. I tried unplugging the temp sensor but the fan still won't come on. I don't have the cooling system manual for the 1KR-FE and I don't have procedures to follow to diagnose the problem. Can any one help me?

Edit:

Coolant levels are good. Engine oil is good. Both sides of the radiator hose are very hot (which I assume means a working water pump and also thermostat, its just the coolant is not being cooled in the radiator).

[tamrat]

I hooked up a multi meter to the cable that carries power to the fan and noticed that it was getting voltage (12V and 24V; I assume this is how the fan can spin in two modes). That meant the system was working and the fan motor was the problem. When I wiggled the terminals the fan came on and off. So it was definitely a loose connection inside the motor.

https://i.imgur.com/05Ph23F.jpg

New OEM replacement fan motor goes for around $260 here. So I decided to rebuild it. Took the motor apart, cleaned it up, tightened up the terminals and also changed the brushes because they were worn down to the lowest point. Everything works perfectly now. And it cost me the equivalent of $2. :D

https://i.imgur.com/V4M032g.jpg

https://i.imgur.com/9jhZ8lz.jpg

https://i.imgur.com/kLatzxf.jpg