What is the name of that heater blower part?

99 Intrepid
The blower fan stopped working on the first, second, and third speed but would still work on the high forth speed.
I replaced the resistor block and all speeds worked again.
About 4 days later the same thing happened and I need another resistor block.
I played with the original one that burnt out and I had a hard time to figure out how it works.
It has 3 coils of different sizes and those put the resistance in the circuit for the first 3 low speeds.
It also has a small electronic device that is the piece that is burnt out and will not allow current to the low speeds.
My question is:
What is this device?
My guess it would read temperature and stop the blower motor until the air was a certain temperature until it allowed the blower to turn on when in the heater mode.
We just got the car so I am unsure how the heater normally works.
Am I right in my assumption here.
Can I bypass this device until I get another blower in?

Thanks

 

You need the resistor block to get differing fan speeds. If you leave it in and it is bad, you will get high speed only but at least your fan works. If you take it out, you will get no fan at all.
You likely need a new blower motor (Autozone seems cheapest) as a new one should last longer than 4 months; you existing motor is probably pulling too many amps thus burning out the resistor block prematurely.
Good luck.