Not sure , but this may be your only option to keep the radio on after turning the truck off.

Mod to Keep Radio ON After Shutting Ignition OFF

Ok peeps, buckle up! This might get bumpy. Don't blame me if you try this and blow your truck up, this is for informational purposes only. If you mess with your wiring, you do so at your own risk! One thing that frankly has rubbed me the wrong way ever since buying my new Ridgeline about 4...

www.ridgelineownersclub.com

 

The mod @Bill_R posted is the only way to get this feature, no vehicle settings exist in the RL to do so.

 

That guirk [edit: quirk] is carried over to the new Passport as well. So if any future plans of the Ridgey resembles the Passport, we’re probably stuck with it there too. Frustrating

 

That guirk is carried over to the new Passport as well. So if any future plans of the Ridgey resembles the Passport, we’re probably stuck with it there too. Frustrating

I'm pretty good with English words, but I had to look guirk up. Turns out I'm pretty good with English words, and may not be alone in latent onset dyslexia.