Hello there, Josiahfromvt.
Great job so far with troubleshooting the auto-brightness on your iPhone. After making sure you have backed up your device, you may want to use the following Knowledge Base article to setup the phone as new to test one last time:
Use iTunes to restore your iOS device to factory settings
http://support.apple.com/kb/ht1414
Once it is restored as new, you can review the steps found here:
iPhone: Hardware troubleshooting
http://support.apple.com/kb/ts2802
Display doesn't adjust brightness automatically
The ambient light sensor brightens the display when using the iPhone in brightly lit environments, and dims the display in low light. To test this sensor, do the following:
- If the iPhone is in a protective case, remove it from the case. If there is a protective film on the display, remove the film.
- Verify that the Auto-Brightness setting (Settings > Brightness and Wallpaper) is set to ON, and that the Brightness level is set near the middle of the slider.
- Press the Home button to return to the Home screen and then press the Sleep/Wake button to lock the iPhone.
- In a bright environment, cover the top third of the iPhone to block the light, then press the Sleep/Wake button or the Home button to wake the phone. Slide the slider to unlock the phone.
- Notice the brightness of the screen and application icons; they should be somewhat dimmed.
- Remove the cover from the top of the display and in a few moments the display should get brighter.
My issue is still not resolved. What do I do next?
Contact Apple Support.
If you need to restore your device with your previous settings, the following article reviews how to restore from both iCloud or iTunes:
iOS: Back up and restore your iOS device with iCloud or iTunes
http://support.apple.com/kb/ht1766
Thanks for reaching out to Apple Support Communities.
Cheers,
Pedro.