I installed a 2 ton airhanler (1st choice) it did not have wire diagram in it,I take it the brown wire is common but not sure what the blue wire is.. it has r.w.g.y bl. Br. Does anyone know.. thank you

Are you using it just for cooling or for heat also? What brand?

I would first check to see if the air filter is clean. Then check (after shutting the power off) to make sure that there is nothing that got sucked into the blower wheel itself.

Is it possible that the heat and air are running at the same time? Sounds like it is firing.

Can you stop the unit and start it in another video so we can hear the difference... hard to hear what you are - sounds like a blower running.