Toyota corolla 92 no heat

Hi, the switch has a cable connected to it, it has definitely come loose from the plastic housing that controls the air flow,suggest open out the panel and reconnect the cable.

take the test.
engine at or over 180F. (y./n)
full heat in other modes, (yes)
front defrost is weak.
weak front only,
1: recirculate is on, turn it off. (mixes cold with hot and net is warm)
2: damper failuire. (not going to defrost postion)
3: bad controls.
3a; some toys have a heater water valve, that i only opens 1/2 way
or is clogged. partially.

the FSM covers these tests, buy the book and see.

no year stated. nor engine.
the engine must be 180F or more and hold
we use what is called a tool, called a thermometer,
we measure the engine heat first. at the thermostat housing
180F is typical. if not fix that first.
check fuses if the fan "blower" is dead , is it?
blows cold in all lever positions? hot + recirc, + defrost ,high or low vents?
all vents cold? (warm)

Need to check the coolant level to ensure that it is full. If full, check the hoses going to the heater core. Both hoses should be hot. If one is much colder than the other, you have a stopped up heater core. If that is fine, check to be sure the engine is getting as hot as it should. A stuck open thermostat will not allow the coolant to heat up enough and not blow hot air. If all that is good, check the blend door under the dash. It may be getting stuck in between the hot cold positions and not allowing all the air to flow over the heater core.

To troubleshoot this types of problem,click the link below :---
Car heater blowing warm, but not hot air?http://schematicsdiagram.blogspot.com/2011/12/car-heater-blowing-warm-but-not-hot-air.html

--------
Engine Overheats and heater blowing cold?

http://howtobyme.blogspot.com/2011/11/engine-overheats-and-heater-blowing.html

---------
Heat blows cold on drivers side and hot on passenger side?

http://schematicsdiagram.blogspot.com/2011/12/heat-blows-cold-on-drivers-side-and-hot.html

-----------
No heat on car? http://technoanswers.blogspot.in/2012/02/no-heat-on-oldsmobile-silhouette.html

------------
Heater blows intermittently and temp gauge goes erratic?

http://technoanswers.blogspot.com/2012/01/heater-blows-intermittently-and-temp.html

------------
Heater blows cold?

http://schematicsdiagram.blogspot.in/2012/02/heater-blows-cold.html

---------
Heater/AC blower motor not working?

http://technoanswers.blogspot.in/2012/02/heaterac-blower-motor-not-working-on.html

------------
A/C, heater, defroster fan, not working? http://technoanswers.blogspot.in/2012/02/ac-heater-defroster-fan-not-working.html Heater problem?

http://technoanswers.blogspot.in/2012/02/heater-problem-on-isuzu-trooper.html

---------

This will help.Thanks.

Sounds like the head gasket is leaking

For this types of problem,i suggest you to check this help links:----Car heater blowing warm, but not hot air?http://schematicsdiagram.blogspot.com/2011/12/car-heater-blowing-warm-but-not-hot-air.html
---------A/C, heater, defroster fan, not working?http://technoanswers.blogspot.in/2012/02/ac-heater-defroster-fan-not-working.html
--------Heater problem?http://technoanswers.blogspot.in/2012/02/heater-problem-on-isuzu-trooper.html
---------Engine Overheats and heater blowing cold?http://howtobyme.blogspot.com/2011/11/engine-overheats-and-heater-blowing.html
-----------Heat blows cold on drivers side and hot on passenger side?http://schematicsdiagram.blogspot.com/2011/12/heat-blows-cold-on-drivers-side-and-hot.html----------------This will help.Thanks.

Sounds like you have air trapped in the heater core when you flushed the heater core. loosen the upper most heater core hose and run the engine untill coolant seeps out. Wait until the coolant has reached running temperature.

The air flow does not 'increase' with the recirc button pressed. The fan motor blows at specific speeds, no matter whether fresh or recirc is selected. The recirc feature is there so that you do NOT admit 'fresh/hot' air from the outside into the AC box. In short, the recirc feature is to re-use, or, recirculate the existing air in the car. When it is properly working, on a hot day, the recirc selection should drop the internal temperature at the center air vent about 6 degrees lower than with the fresh selected.

the unit were you turn on the fan leaks vacuum which causes the vents not to blow properly the unit is not expensive for it is plastic comes with fan switch ex..