Q&A

 Master

I would check the thermostat, i would also check the heater core. This 2 things could be causing you low heating or no heating at all.

 Journeyman

If there is still heat but no flow, your issue is most likely the blower motor. Depending on how it failed, it may have taken the resistor with it. I would start by checking for battery voltage between the large lead going to the blower motor and ground. If the motor is suspect, you will have voltage there. You should have voltage at this terminal at whatever speed other than off is selected.

After replacing the blower, if you only have high speed and none of the lower speeds replace the blower resistor.