I think my HVAC has low air flow at vents. I have cleaned blower fan and replaced filter. Motor rotates by hand freely. Connections tight. Could this be bad run capacitor?

I think my HVAC has low air flow at vents. I have cleaned blower fan and replaced filter. Motor rotates by hand freely. Connections tight. Could this be bad run capacitor?

It is possible that the capacitor is weak but you will need a tester to be sure or just replace the capacitor with a like same value.

It is also possible that if you have a A/C coil in your furnace the back side could have got dirty over time.