Toyota Repair: 90 toyota heater problems, heater control valve, blower wheel

Question
my heater will only run on the high setting and is very very loud. When on high it wont put out tons of heat. Please help me solve this problem because winter is coming.

Answer
Ben,

If your heater is making noise you either have a bad fan blower motor or there is debris like leaves caught in the blower wheel. That throws it out of balance causing it to vibrate like crazy.

Second, how long ago did you replace that thermostat and gasket? If it opens early the engine won't fully warm up and your heater output will be low.  Also, check that the radiator is full of coolant. The last item, there is a heater control valve usually mounted on the firewall. Make sure when you move the temp selector to hot that the cable opens that valve all the way.