Defroster not working

General Discussion
1

I have a 2010 corolla seems the front window defroster isn’t working. Heat, air, and rear defroster works fine. Any suggestions?

2

Without details, I’d guess you have a blend door problem. When you say it isn’t working do you mean no air comes out the defrost vents, or do you mean that air comes out, but it never clears the window?

Is it actual frost on the window, or is it just condensation?

3

No air coming out defroster just heater

4

sounds like a mode door problem

5

Does the blower motor seem to be working? You should be able hear it spinning and vary in pitch when you change the speed in defrost mode. If that seems ok, then I expect you have a problem associated with the Damper (or sometime referred to as Air Mix) Servo Motor.

Before going down that route, you should verify again that the AC is working 100% b/c AC mode is used for the defrosting function probably. Debugging this beyond a look-see under the dash for loose wires & broken connectors etc may require the Toyota scan tool b/c the body control module CAN-buss is involved.

6

Ac and heat works great very little air comes out on defroster though.

7

So when “defrost” is selected along w/AC or w/Heat, still getting plenty of air out the other ports? If so that means the blower motor is working correctly, and that the problem must be an obstruction of some kind preventing flow to the defrost pathway. Good chance that is a door actuator problem. One idea you could try is to disconnect the battery overnight say When you reconnect it the next morning the computers will go through their reset functions. Sometimes the actuator motor gets confused and the computer can’t figure out which position it is in. Resetting can put it in a known position. Worth a shot anyway. One downside w/disconnecting the battery, the car may have to go through a re-learn procedure, so it might not idle very well until that is completed.

8

We just put in a new battery couple months ago, like I said everything else works, but front defroster puts out little air.

9

Have you ever fixed your computer just by turning it off, then back on again?

10

Yes but will try the battery thing next day off.

11

How do u turn that off?

12

Disconnecting the battery is the only way to turn all the computers in the car completely off.

13

Ok thanks will try next day off, because it worked fine until battery change.

14
  • Buttons Stuck : In some cases a button or knob for the heating controls becomes stuck. Moving them back and forth until it moves into the defroster position may solve this problem.
  • Blocked fresh air intake : The fresh air intake is at the base of the windshield. It draws in fresh air, which helps the defroster function. If leaves or other debris are blocking the air intake it will affect the defroster.
  • Vent Issues : If the vents on the dashboard are clogged, this will prevent the air from reaching the windshield. A quick vacuuming of the vents may fix the issue, if not the clog may be deeper in the system and require a professional.
  • Low Anti-Freeze : The heater core depends on hot antifreeze moving through it to heat the inside of the car. If the vehicle is low on antifreeze, it can affect the heating and defrosting systems. Anti-freeze should be checked and replaced on a regular schedule.
  • Malfunctioning Thermostat : The thermostat in a car works like a shut-off valve between the radiator and the engine. It remains closed when the car is first started to build up heat. Once the engine is warm the thermostat opens up to circulate anti-freeze to prevent the engine from overheating. If the thermostat is stuck open, the engine doesn’t warm up, so the defroster will not have the warm air it needs to function properly.
  • Bad Heater Core : The heater core is basically a mini radiator that is located behind your dashboard. It is the heart of the heating system and essential to the defrosting system. There are a number of things that can cause a heating core to go bad, it can become clogged up due to contaminants in the anti-freeze, hoses can come loose or broken and control valves can become stuck. A bad heater core will result in no heat, which means a non-functioning defroster.
  • Bad Blower : The heating and defrosting system rely on an electric blower motor to move the hot air into the cabin of the car and through the defroster vents. If the blower motor is malfunctioning, the defroster will not work. Issues can range from a blown fuse to a bad blower speed controller. The blower motor itself can also go bad and need replacement.