Xantrex Fredom 458 series inverter/charger 20 amp

If the mechanic miswired the batteries and created a reverse polarity condition, the inverter may be toast. See #8 on page 22 of the owners manual. It can be downloaded. However, there isn't a test to determine if reverse polarity occured. That will require a call Xantrex.

Otherwise, according to the manual the lights are saying that the inverter is ready. According to page 6, there may be onboard branch circuit breakers. Have those been reset?