Heat and ac blower sound normal but very little air is moving inside the cabin. What can cause this?

Very little air from Defrost? Floor? Panel Vents? With it on Inside Air position? Does Blower work on all speeds? Let's start there.

Vent doors not open correct

Air Temperature Control Blend Door Failure No Heat or no AC (dependes on where door sticks)

In all modern cars there is a tiny DC electric motor driven gear drive that moves a plastic door that blends heated and cooled air from the AC and the heater core, this is called (interestedly enough) the air temperature control blend door actuator. The motor that moves this door fails because the door starts sticking from warping, most common complaint is no heat but it can be no AC as well. To replace these parts (blend door and blend door actuator) you must remove the entire dash from the car. Always have this problem confirmed by a dealer or qualified repair shop as it is a very expensive repair.

Other causes of no heat in the cabin are engine thermostats that are stuck open (engine runs cold) or air bubbles in the cooling system.

Is the issue there when using heat and air-con?
If so, then check the blower motor and fan switch for fault.

Check any cabin air filter if fitted for clogging.

If only an issue with hot air flow, then check the heater matrix hasn't bunged up.

If only a cold air flow, then check the air conditioning car evaporator in the cabin for signs of clogging.

Clogging can be more of an issue in pet owner's cars as pet hair readily clogs up these two components in cars fitted with no interior air cleaner element/filter.

Normal, the ac heat exchanger condenser need air moving across the fins to remove the heat. While moving in town the condenser isn't remove the meat that is building up the it's aluminum fins. Even though the vehicle uses an electric fan. The fan is used to cool the engine temperature. If you Toyota is equip-ed with automatic transmission. The electric fan will need to pull enough air to cool the engine temperature, automatic transmission fluid, air conditioner condenser, and maybe power steering condenser to cool the power steering fluid. Later model of vehicles/trucks are using different refrigerants instead R134A in which you Toyota uses.

The simples way to explain is the ac remove heat from inside your Toyota and this heat is removed by the refrigerants inside your ac in the car. To cool the refrigerant this coolant is removed to the heat exchanger condenser located in front of the engine radiator. So, while moving at 60mph there is enough air flow through the radiator, ac head condenser, and other aluminum heat exchangers. GB...stewbison

No, not really. What I mean it is not really directed for the AC, HOWEVER, what it is is a cabin air filter, which of course helps with the ac, heat and vent flow. Which indirectly will allow your ac to flow better and take away some of this wet moldy smells cause from moisture.

This type of filter is normally removable from somewhere in the glove compartment area. It sits in between the fan blower and the cooling evaporator. It provides cleaner internal air and also keeps the evaporator from clogging up which would affect cooling.

However, in that year supposly there is no cabin air filter, but The Haynes manual, although covering 1993 to 2004, says it's in the blower assembly and NAPA is willing to sell a part alleged to be a cabin air filter for a 2001 Altima.Now, i do know there is after market adaption cabin filter that a person can put on, however, in less you had a bad problem it would not be most likely worth the cost and trouble. I hope this helps some. Thanks Mike

Cabin air filter plugged?

check the sensor on the front of the engine ,by the water pump.i It will usually have a single little plug on it

are you getting any air into cabin?? cause if you ar getting air but its not coming out hot then it may be a bad heater control valve. If you are not getting any air period then its a bad blower motor or blower motor relay.

Sounds like the blower resistor module needs to be replaced. Could also be the switch.