Hey 1Danette!
This seems to be a common issue with newer iPhones in Cadillacs. The camera bump on the iPhone prevents the phone from lying completely flat on the wireless charging pad which messes up coil alignment and stops charging from working properly.
The first thing to do is test the pad with another phone. If another device charges fine then the issue is likely alignment not the charger itself.
Some people say that using a MagSafe case helped the phone charge properly.
Another trick people say is to place something like a few folded Post-It notes or a piece of foam at the bottom of the charging slot. This raises the phone just enough to align the charging coils better between the phone and the pad.
Good luck!