The furnace kicks on, and most of the time the fan/ blower does too. But there are some times that the fan/ blower doesn't. Though it sounds like it's trying to kick on.
When the heat is turned off the fan will come on by turning the thermostat to fan.

I get Nordyne Model KG6RA 096C-- 12B
Serial #: KGD060902657

Hi Asunset and welcome, I would suspect the fan relay is going south. You say "it sounds like it's trying to kick on", is the sound coming from the relay?