The fan blower, even after changing it to cool -giving hot air

Is the coolant level full ? Are the heater hoses hot to the touch ? Do you know where the heater hoses are ? Out in the engine compartment going through the fire wall into the passenger compartment . 2 hoses , one carries hot coolant into the heater core the other is a return back to the cooling system . If hoses are hot you have a temp. door not working . When warmed up what does temp gauge show ?
Temperature Control
The temperature control operates in the following manner:

• Temperature control of the manual A/C-heater system is determined by the position of the temperature control knob (between COOL and WARM).
• This control knob is connected to a potentiometer mounted in the integrated control panel. This potentiometer is electrically connected to the A/C electronic blend door actuator that operates the A/C air temperature control door.
• The A/C electronic blend door actuator contains a reversible electric motor, another potentiometer and a printed circuit board. The wiper of the potentiometer is connected to the actuator output shaft and moves with the output shaft to indicate the position of the A/C air temperature control door.
• Battery voltage is applied to the ends of each potentiometer. The voltage available at each wiper indicates the position of the potentiometer. The printed circuit board drives the actuator in whichever direction is necessary to make the actuator wiper voltage agree with the control wiper voltage.

System uses a reheat method to provide conditioned air to passenger compartment.

• All airflow from the blower motor (18527) passes through the A/C evaporator housing where it can be cooled and dehumidified.
• Temperature is then regulated by reheating a portion of the cooled dry air and blending it with the remaining cool air to the desired temperature.
• Temperature blending is varied by the A/C air temperature control door which regulates the amount of cooled air that flows through and around the heater core (18476), where it is mixed and distributed.

no the pipes should not be cold and wet but if you just have stop using the aircon recently it will do that for a while till all the gas is out of the system so yes its sorta normal

Search for my prior solution under Nitram2. It's almost always broken wires in a 3-wire harness feeding the knobs. Toyota will skim you close to $1000 for this, claiming that you need to replace the control board. It's an easy half-hour soldering job.

mode door or actuator not functioning properly

You have a problem wit the air temperature control blend or the blend door actuator motor, most times both are defective. The parts are located deep in the dash and as such the dash assembly must be removed to service the parts.

I can tell you about my experience on my 1999 F150. I do not believe it is the blower control switch because mine went out and only affected the fan speed. On my truck, in an incident like yours, I could not get a good response from the temperature switch.

I would turn the control and it would hit a stop on both ends, but the temperature would not change to match the switch. What I found is the stem of the temperature control did not turn because the knob cracked behind the switch. There is a half-moon shaped metal clip inside the plastic temperature knob. The clip can spin when the knob is cracked and nothing moves right.

Because the plastic knob has molded stops under the knob, from the drivers point of view, the knob was turning lock to lock. In reality, the stem was not turning. Try taking the knob off and turning the stem with pliers wrapped in cloth to protect the plastic. Then see if the temperature changes.

Radiator Thermostat - It is at the other end of the lower rubber hose of the radiator where the hose itself terminates on the engine- it is called thermostat housing.

For Ac unit - if manual adjustment- just like and ordinary thermostat of the air conditioner it is the knob where you adjust the temperature.

If electronic/digital type need to change whole assembly.

check your cooling level and check for coolant leak, if you don't have enough coolant it won't get hot

Hi - There may be 2 separate problems. On my 1991 Lincoln Town Car, there is a Thermal Blower Lockout sensor that disables the heater from blowing until the engine temperature reaches a specific temperature. This way if you have vent or floor settings and 90 degrees set and it is winter, you won't get blasted with cold air. When the vehicle warms up, the TBL circuit enables the climate control to blow the hot air. If you use the flr/def instead of the floor or vent control, the TBL should not prevent the heater from working even with a cold engine. On my car, the TBL went bad and always prevented hot air from blowing on the floor and vent settings, even when the engine was hot. Another thing to check is a thermal limitor resistor. It is designed to cut off the blower at very hot temperatures, except if the blower fan is in the hi setting.

As far as the A/C is concerned, can you verify if the clutch is engaging or not? A rapid cycling of the clutch is an indication of low freon. If you are absolutely sure that you are fully charged on freon, I think there are 2 possible causes: (1) Bad pressure switch on the accumulator is indicating low freon that is telling the compressor not to work; (2) a blocked orifice tube.

Hi!
It appears we have an Air lock scenario and you will need to perform a system Bleed.
Park the vehicle on level ground, when cold remove coolant filler cap, start engine and leave to idle, turn heater on full and blower to max. When engine reaches operating temperature watch and listen near coolant filler, keep clear as gurgling and hopefully a boil over should occur. Top up with very warm coolant and wait as it may do it again.
Check for heat inside vehicle if warm replace coolant cap but keep an eye on temperature gauge as the ~Air lock may have moved on from heater matrix/core so proceedure needs to be carried out again from COLD.

Please press the Blue button to appraise my FREE Efforts, Thank You!
Paul 'W' U.K