My blower motor wont blow

SOURCE: A/C will suddenly send out heat. Fiddling with knobs seems to help. What's wrong?

You have a broken wire connection between the temperature control knob and the circuit board behind the center dash console. Vibration causes the failure and once the control knob gets loose the solder connection fails.

For someone that knows how to remove the dash unit and can re-solder a couple of new wires this fix should take no more than 1 hour. Make sure that you apply loctite to the heat control knob spindle nut when you re-assemble it.

The dealer quoted me 750 dollars to fix this issue and I found out that it's a common failure for this year. I fixed mine virtually for free but it took some tools and about an hour of my time.

SOURCE: blower motor resistor

Two bolts a little neck twisting 5 mins...
Look under the dash follow the wiring from the blower any two of them will lead you to the resistor. It's in the air box about.

SOURCE: 2004 sienna heating system problem

try turning the blower down, if you have the fan on full you will feel cooler air from time to time. as the thermostat only measures the ambient tempreture inside the car when this level is met then it will turn off the heat so it will only blow the air from the car which will feel cooler.
if the car is still cold suspect the tempreture control in the car maybe faulty or the water level in the system maybe low.

SOURCE: PREVIA 1992 NO HEAT

If your Previa's low/medium speeds on the blower (ac/heat fan) have stopped working, but the high speed works, you most likely have a problem with your blower motor resistor. Here's how to access the resistor. These directions may be slightly incorrect since I finished this procedure about an hour ago and I'm typing this from memory. But they should get the job done. It took me about 30-40 minutes to do this from start to finish:

Remove cabin air intake duct (two philips screws)
Remove one bolt holding antifreeze reservoir in place, move reservoir aside.
Remove two bolts holding brake fluid reservoir in place, move reservoir aside.
Unsnap recirculate/fresh selector cable from blower housing (on vehicle-left side of housing)
Remove angled metal arm from vehicle-right side of blower housing (attaches to firewall with nut and to housing with bolt).
Remove two bolts (at vehicle-front of housing) that hold the upper and lower blower housings together.
Remove nuts on firewall holding upper blower housing in place, and begin to work upper housing out of vehicle, disconnecting the 4 electrical connectors as needed (2 connectors are on top and 2 are down beneath the blower housing).
Remove nuts on firewall holding lower blower housing in place, and remove lower blower housing from vehicle

Look on the lower blower housing, on the side which was facing the firewall, and you'll see a white ceramic block (approx 2-3 inches long). This is the blower motor resistor. There are 2 contacts on the resistor that should be joined by a springy curved band. If the band isn't bridging the two contacts, it's likely that the soldier has melted/broken, and this is what's causing the low/med speeds to not work. Solder the band back in place and this should correct the problem (it did for me).

SOURCE: I have a 1992 Toyota Previa. The heater stopped

the last year, your blower resistor has been bad, now your motor is bad. rap on the motor and see if it start to run, if so, replace the motor and the resistor.