92 PA Blower Motor for Heater works intermittently

The blower motor for my heater only works intermittenly. It has been getting worse over time. It started acting up around the begining of summer but hardly works at all now. Not good with the snow and ice coming to New England! I should have taken care of it when it was warm.
I am not sure if it is the motor or the switch itself. Nor do I have a clue on how to go about trouble shooting it. I was thinking of maybe putting in a toggle switch direct to the motor.

Any ideas would be welcome.