What will cause my heater to come on only sometimes

What is your question?

I just here like it wants to start up then the problem is all the time I don't know if it's my blower resistor is that possible I turn my heater on an It will sound like it wants to turn on but won't and then it will just randomly just start up the dealer ship i purchased it said they put a new blower motor in it so what could be the problem

What makes this problem better or worse?

N/A

How long has your 2016 Dodge Dart had this problem?

2 months