the motor may run hot or sound funny if the cap is too far out of range.
if the motor runs at full speed in one direction and doesn't sound funny, it's probably not damaged.
i would be suspect of the directional switch, it may be defective in the reverse direction.
to test a capacitor you'll need an analog ohm meter or a digital meter with capacitor test capability .
Warning: a capacitor can kill you if you don't discharge a charged capacitor.
to discharge, i use a plastic handled screw driver across both terminals of the capacitor (or all 3 if equipped as a dual capacitor)
(no metal cap on the handle)
i discharge every capacitor i put my hands on before attempting any measurement.
you may not get a second chance , so treat it like it's a rattlesnake until you discharge it!!!!!
Disconnect capacitor from motor leads
you'll put your ohm meter leads across both terminals of the capacitor not the motor,
if the capacitor is good your needle on the ohm meter will start moving away from the infinity symbol(looks like a figure 8 on it's side), towards the right side of the analog meters face.
when the capacitor charges up the needle will rebound and start returning to infinity.
you are effectively charging the capacitor with the ohm meter's battery .
if the needle doesn't move your capacitor is known as OPEN and is defective
move one lead to the case of the capacitor while keeping one lead on one terminal, if you get a reading the capacitor is shorted to the case.
then test other cap terminal to case to complete case short testing.
if no reading is seen the capacitor is not shorted to the case.
a capacitor can short internally, which will detrimentally affect it's output.
if it's a start cap the motor may not start, if it's a run cap the motor may start but not run, or run slow or very hot.
Capacitors are not usually repairable, don't be tempted to crack open the cap's case, carcinogenic materials can be found in a lot of capacitors, plus liquid filled cap's makes quite a mess upon opening ( don't ask how i know that...
))
i hope the info helps out
