Fan motor does not stay on - 2001 Toyota Echo

It will if you have airconditioner on.but should turn off after car is shut off and cools down.

Disconnect the ECT (engine coolant temperature) sensor with the key on, the fan should start in default and stay running, if it doesn't run check for voltage at the fan motor connector, if voltage is present and the connector is not burned looking or discolored replace the fan motor. If the fan has no power try jumping the relay socket to power up the fan motor circuit, if that works replace the fan motor relay under the hood. You gave no make, model or year and engine type so that is about all I can help.

The fan speed reostat is broken or the switch itself is bad. Try replacing the switch first because the motor speed reostat is part of the motor itself. $$$

What a pickle. How long did you give it before you disconnected the battery? You know, most fans may continue running for a short time, especially on a car that has been running at normal temperature for awhile. Reason being, the engine will actually get hotter for a bit as the coolant is no longer circulating. The fans shouldn't stay on too long. Most I have seen, less than a minute.

Be that as it may, a temporary solution to the problem, instead of disconnecting the battery to stop the fan-this is not good for the computer circuits who like steady voltage, however small-is to instead pull the fuse for the cooling fan. This is a large (80amp) maxifuse in the Battery Junction Box. The position in the box is F-29.
If it is staying on too long, the bad part appears to be a module or some type of relay-like switching device right at the fan motor itself. There are 3 wires to the fan assembly. One is the power feed from the aforementioned fuse, one is a command signal from the PCM to turn the fan on, and the last is a ground for the motor and assembly. I hope you could detach this device from the fan motor for replacement. Certainly nothing wrong with the fan motor itself. Good luck.

Blower motor resister is bad.Easy to remove,it's located by blower motor,click here to see what it looks like.

short in the switch- worn out /or a bad fan motor

This is normal. The fan will run with the engine off till the rad temperature goes below about 100 degrees F. Do not worry about this only if the fan stays on longer than 10 minutes. You may need a new fan relay if it won't go off. Good luck!

The power connection to the fan motor on these is known to overheat and cause a bad connection.The fan motor is above the passengers feet.Next time the fan motor will not come on, switch the selector to high and wack the bottom of the dash above the passengers feet.If the motor does come on at that time,you may need a replacement fan motor and connector.REPLACE the fan speed resistor board when replacing the fan motor,which is right behind the fan motor.

The brushes get worn down on these motors. Your "give it a boost" description leads me to believe this is your problem. You can replace the brushes without buying new motors if you find a place to buy them.

do you have a mechanical or a electric fan?
acording to your question seems to be electrical make sure the fan nut is tie and there is no cracks on blades
also wigle the ft shaft up and down and if you feel any play the replace the motor