I d start by.
Furnace blower motor relay test.
In a blower motor the relay supplies the power that allows the fans to circulate warmed air.
Essentially an on off switch the blower motor relay s reactions start and end the heating process in hvac systems by controlling the flow of current between the power source and the motor.
Hvac blower fan test diagnosis faqs q a on fixing the air handler fan questions.
Sounds like a stuck fan relay or shorted wires to the relay.
Reader questions responses help.
Hvac blower fan testing diagnostic questions answers.
The relay by the fuses clicks when i turn the fan control knob from 0 to 1.
I go over how to read the ratings for time how to.
This video will show you how to properly diagnose your blower by using the multime.