Electronics issues after installing amplifier/subwoofer

I'm having an odd issue with my 2016 CX-5 after installing an amplifier and subwoofer using a PAC line out converter. I did not splice into any factory wiring and always had the battery disconnected during the installation. I've since disconnected all of the above and the issue remains. Sometimes this behavior happens immediately on startup and sometimes it happens 2-5 mins after start up (and once they occur, they don't resolve until the car is turned off, which only sometimes works).

The set of issues (they all occur together or not at all):
1. The fuel/trip display does not turn on (or turns off)
2. The Security Indicator Light continues to flash (even after the the car is on)
3. The Key warning light illuminates red
4. The reverse camera does not kick in when in reverse. The infotainment screen otherwise works normally.
5. The indicator light on the gear selector (to indicate which gear the car is

Car has no issue starting. Battery is strong. Thanks for your help.

My initial gut reaction to this is somehow inadvertently you have disturbed a ground wire in a connector.

what did you disturb during your installation? If you did not splice into any factory wiring, did you use a pre-fabbed connector of some sort? I'm guessing the PAC connector was for 2 (or 4) RCAs...yes? Was there a ground wire on that box too and did you connect it? I know that is only supposed to help with noise in the RCA (low level) signal, but I'm just trying to ask more questions to get a better picture of your predicament.

Do you think it is just coincidence. And since the issues persists w/the equipment disconnected, you might as well connect them back up and enjoy the music.

Have you tried adding more ground wires in the engine bay? I can' remember what it is technically called, but basically you run various 12AWG - 8AWG (crimped) wires from the Fender > block > valve cover > trans housing > ? > Fender by linking up to different ground points on each piece AVOIDING any moving parts of course. I remember reading that doing this established a "larger" ground plane helping remove any resistance that might be experienced as most automotive ground wires are tiny and points are scattered all over the place.

You might have to go back and touch every thing you touched on the intall and un-install to see if something got kinked or nudged or stressed to the point it is causing an error.

A lot of the errors sound like they are connected to the radio unit behind the glove box or center console area.

Appreciate the suggestions but I've fixed the issue and I'm fairly certain what caused it.

Because of the keyless entry system that automatically locks the car when exiting the vehicle, I found that I had to use the physical key inside the fob to unlock the car after disconnecting the battery. I think the car didn't like that and it somehow tripped the security system. I was able to resolve this issue by disconnecting the battery for ~20 mins before reconnecting.

After a day of verifying the issue was resolved, I went back and re-connected the subwoofer and PAC adapter but this time I made sure all the doors were unlocked before disconnecting the battery (and therefore didn't have to us the physical key) and sure enough the issue did re-appear.

glad you got it sorted...it is amazing how sensitive new cars can be when disconnected from their battery.

Maybe, in the future, just pulling the fuses for the systems you are working on would be more prudent than disconnecting the battery...I know, I know, disconnecting the battery is the safe way to work on electronic....but...this is only a thought.

Now that I know to make sure the doors are unlocked before disconnecting the battery, I've had no issues. I've probably disconnected 5 times since and have never had the issue since.