Hopefully they wired the awning though the 'house' accessory fuse block. I'd start by gaining access to the back of the panel that houses the awning switch and with a trouble light or V/A meter, check for power at the rocker switch. If no power there, go to the 'house' acc. fuse block and check for a blown fuse...being an 'add on', I'd check any unmarked installed fuses first or one that is labeled as 'body builder' or similar. If you do have power to the switch, check for power out of the switch with the switch activated. If you have power out, then I'd go to the motor and check for power there. If no power at the motor, probably a bad wire between the switch and the motor. Power at the motor=bad motor or look to see if there's a 'reset' button on the motor.
If 'Ugh' got involved with the install of the awning, he could have spliced into another circuit. Check to see if any other systems or fixture is not working. If so, check that circuit's fuse.
Of course, most awnings are wired for some prerequisites or lockouts, like the engine ignition can't be on for awning extension. Electron chasing can be interesting. Good luck. Bob