Hi @jargs ,

What is the make and model number of the fan?

Post an image of the capacitor in question showing the markings and the wiring etc.

Here's how to do this on iFixit Bilder zu einer vorhandenen Frage hinzufügen.

Are the two white wires joined together or even the terminals they're connected to, are they joined together? It may be that they are just in multiple connection for the supply in the fan.

Disconnect the wires from the capacitor and then use an Ohmmeter to test between the capacitor terminals where the two white wires were connected and check if they are short circuit.

Also some DMMs (digital multimeter) have a capacitance test function which you may be able to use to test the 4uF capacitor (if the meter’s capacitance test range is this high). Discharge the capacitor first before testing i.e. short out the red wire terminal to the white wire terminal (or both?) for a few seconds.

The 4uF is necessary to get the correct current (i.e. therefore speed) for the fan.

Also don’t assume that the red is the hot wire. In some places the white wire is the active wire in electrical appliance wiring. ;-)