Tried doing a sub install and when I got everything plugged up, I started the car then then radio and 12v lost power. I have checked all the fuses with a tester and they are all good, both under the hood and dash. I can not figure this out and wanted to reach out before I took it to get looked at. Any other possibilities aside from fuses? I have even tried a new radio.

 

Under-dash Fuse No. 32 (7.5A) is the fuse in common for both the audio unit and the accessory power socket. There should be power through that fuse when the ignition switch is in the ACC (I) or ON (II) positions.


Have you checked whether there is power on both sides of that fuse when the ignition switch is in the ACC or ON position? If you have a voltmeter, measure the voltage.