Starting with the most basic, I assume:
The vehicle was running (outlets only work when running.)
You turned on the main switch up by the steering wheel.
If yes to both of these, it's possible the protection circuit was activated. Below is the verbatim from them manual. It also has the process for resetting this circuit.
Hope this helps.
The protection circuit may be activated to cut the power supply if any of the following conditions apply:
●The engine is started with the power outlet main switch on.
●Use of electrical appliances exceeding the maximum capacity is attempted.
A sound may be heard when the protection circuit is activated. This is nor- mal and does not indicate a malfunction.
●Electrical appliances, which consume power exceeding 100 W, have been used continuously for a long time period.
●The total power usage by all electrical features (headlights, air conditioning, etc.) has exceeded the total vehicle maximum for an extended period of time.