Help troubleshooting Wiring, Timer and Motor

I have a Pentair whisperflo with century 3/4hp 115/230V B847 single phase motor and Intermatic 104 Timer.

One day it all just stopped. The motor had been making loud noises. The Timer on my Intermatic was acting fussy and is now stuck. I can’t rotate it at all. And possibly the main culprit, the wiring was reading 0-12V at the red and black hot wires at the Timer. The timer is 40 feet from the breaker box. The 3 wires travel 40’ from the breaker box undergaround to the timer. So I have electrical questions and other questions…

Is 12g wire big enough? I have 15 amp double pole circuit with a run of 40’ from box to Timer. I’m fairly certain the wires have been damaged underground because of the reading my multimeter gave me 0-12V.

It’s confusing because the motor was also making a loud noise before everything died. I opened up the motor. The bearings turn but not very well. The capacitor is fine. The Timer clock is totally stuck. I can’t rotate it at all. The two hot wires at the timer box read 0-12. This is where they come up from underground after about 40’ from the breaker box. So it’s clear the wires are bad but the loud noise from the motor and the timer clock being stuck. I mean can all 3 things go at once? My one hope is that the motor is savable. Maybe I will hard wire it with the PSC attached to see if it starts. It is completely taken apart.

There is a lot going on. And no I can not afford an electrician.

Help?

Not sure how to attach pictures.