Hello, yes you can get a 5 uf run capacity for the fan motor the voltage rating is important. thats the volts out of the capacitor... it can be very high 370 to 440. try to match what the motor mfgr specifies. you might get by with 370v on a fan motor though (its low torque)
If the compressor doesn't run try using a well insulted screw driver to push the contractor closed, see if it runs.
... in that case...if it runs then the problem is in your control circuit. If it doesn't run, check power to it. If thats fine, kill all the power, triple check that its OFF, then triple check it again.
Then pull the wires off of the compressor and check using an OHM meter to ground...any read at all = bad compressor. then check OHMS C to R, C to S, and R to S. R to S should add up to total reads you get on C to R and C to S
any infinite resistance reads indicate an open internal over load.. if the compressor is cool and the internal overload is open... its toast.
these will be low resistance reads, in the 1 to 7 ohm range each. If thats good and the compressor just hums when you shove in the contactor, check its run capacitor again... if it sparked it was probably OK... (watch out however those can explode)
Do all that and get back to me.