Aftermarket head unit USB question

Meaning I do not have a extra USB output on the rear of my radio now so the USB that is on the dash is not powered and is now useless. Found a 12v to 5v mini USB adapter I may try.
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I think the port in your truck takes the USB mini plug, so if this adapter works you would still have the charge port. I tried using a USB splitter on my Kenwood ddx470 but so far that hasn't worked. I have not tried to figure out why, I think it's because I have so may adapters from regular to splitter to mini ect.