What services should be performed on the air side components of An fan coil?

First you should lockout/tag out, then visually inspect the blades on the squirrel cage to insure that they are free of debris, after making sure that all mounting bolts are in and tight, you should then energize the unit. and take both a start and a run amp draws off of the common/neutral wire from motor then you can assess how well the motor is electrically by comparing to the listed RLA

on data plate. The actual amp draw should be around 65-80% of listed number also the start up amps should be about 8 times the run amps.

If the unit is a permanent split capacitor motor then while the circuit is still denergized take a screwdriver or other metallic conductor and short across the terminals to ground this is important because failing to discharge cap can be deadly, now you can remove the 2 brown wires off of there terminals on capacitor, stick meter leads to capacitors terminals and take the measurement of microfarad's these need to be plus or minus 6 percent of rating printed on capacitors label. after these measurement's have be taken, you can clean fan if needed