What i mean by after furnace shuts down the blower motor continues to run but at a lower rpm. This furnace has no capacitor i had the central air added later everything worked fine until the last couple of weeks.

i have replaced t-stat,fan relay switch along with the tranformer,sequencer and limit switches but the blower still runs but at a much lower rpm after the furnace shuts down it heats normal and the ac cools normal.