Replaced blower motor and now it won't turn off

A repair technician replaced my blower motor because it stopped working, now the fan constantly runs.

1. I hear the inducer fan start.
2. I hear the furnace ignite.
3. I hear the blower running.
4. Furnace turns off, but the blower keeps going until the next cycle.

The blower hasn't stopped. I called the repair tech and he said it might be a bad circuit board. Is it possible that the new blower motor may have been wired incorrectly?

I've read numerous threads and saw that it might be:

a. Thermostat: this is four months old and wasn't touched when the blower motor was installed.
b. Relay switch: can this go bad with a motor?
c. Limit switch: maybe this because when the motor completely died, the furnace would burn for a minute, get too hot, then shut off (didn't know the blower was out at this time).
d. Motor might be wired incorrectly.

Any advice would be greatly appreciated. Thanks!

 

A make and model of your furnace would be helpful.

Many blowers come on 45 seconds after the burner lights and then turn of in xx seconds. The off time is usually set with a jumper plug. If the plug fell off I'm not sure if the blower goes to max time before shutting off or it just won't shut off at all.

I'm guessing if you shut the power off to the furnace the blower will shut off until the next call for heat..... is that correct ?

 

Blower relay could be sticking, R and G could be arching somewhere in the low voltage wiring such as wiring in the back of the tstat or in the cabinet. Wiring it incorrectly isn't really a concern of mine they are very basic.