First off, welcome to the forum! Here you will be able to learn lots of fun and interesting things.
Most likely, the backup camera is not turn on through the radio. There are a couple of obtuse settings that Winnebago uses to control it. Search in the Winnebago forum here for a couple of other threads discussing how to resolve this issue.
What type of MH do you have? What year is it? Can you tell us what radio you have?
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Colorado '15 Winnebago Forza 34T w/MKZ hybrid toad '20 Jeep Cherokee Trailhawk toad