Hi,

If the fan doesn't run, the A/C compressor won't stay on very long, due to the high heat buildup. The compressor has a thermal protector to prevent destruction of the compressor.start with turning off the power to the unit so you can visually check all the connections inside the access panel on the unit. You're looking to see that all the terminals are intact and on the lugs inside the unit are not rusted away or badly corroded.If all the connections look OK, you need to restore power and use the meter to check for voltage through the components.

check if the fan motor is getting power, as it could be as simple as a bad start capacitor of a burnt out motor needing replacement. Before you start buying parts, it is recommended that you do a complete check of the unit to make sure you determine the faulty parts

Thanks
Smith