Well, let's try this. First of all an inverter takes 12 v power and allows you to use AC with it. Inverters are usually added as aftermarket items to an RV when you have a large battery array and/or solar. Are you sure you have one? Typically , if installed, you don't need to turn it on...it is integrated into your power system.
You shouldn't have to do anything to use your 12 volt power in your unit. That is assuming you have a charged battery or are plugged into AC. The converter will take the AC and move it to 12 v. So, most of the light fixtures, etc are wired for 12 v already.
Again, this is assuming that your converter is working.
It is pretty late so
I am not sure if this is helping any. Maybe someone who has a better understanding of rv power can chime in.
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