Reinstall the Cruise Control unit if you removed it. Plugin the A/C cable if you unplugged it.

Reinstall the battery If you removed it. Connect the Positive (+) terminal first then the Negative (-) terminal.

Start your car and with the engine running use your multimeter on DC Voltage range to check you and above 14V at your battery terminals.

If everything is good, turn off your engine. Reinstall your plastic cover.