XG350 electrical system

Yes, but I made a big mistake, even when I did made the connections properly, I didn't disconnect the ground battery. The new device started to fail after I unpluged the iPhone from its attached socket, so I re-installed the old one for a while. After disconnecting the old one (again today) and installing the new one -to show in the video the failures- the car electric system started to fail: The AC comes On everytime I turn the ignition key On, the gauges of the fuel and temperature are frozen and won't go down, the car door light won't come on when the car is Off but they work with the car On, the electric door locks work with manual use of the key but won't work with remote control, the flashing light work but the clock won't do it.

About the new device, the problem was primary the losing of the screen with lines like interference until the screen came blank.

I have disconnected everything, this is to say, antennas and whole wires are loose, nothing is connected to the radio system, neither the speakers. I have disconnected both battery terminals for a few minutes, I have checked all the fuses, and the problem still the same. I have the feeling that if not a grounding problem, something needs to be reset.

I know that it is my mistake to install the new device without disconnecting first the ground terminal, but now I want to know what to do to fix this problem.

Thanks! I replaced the fuse for the clock and the system appeared to be back to normal. Everything works, except the new receiver because I have not installed it back yet.

Please, I still have a question, why a blown fuse for the clock can mess up to many things, specially making the AC coming On by itself when you turn the key on ignition?

I'm glad I asked you for the solution, as an amateur who loves fixing (messing up) his car, I learn a lot and obtain more experience from experts like you.

Thanks again, but please don't forget to give me a brief explanation of how it happens that the AC is related and affected by the clock/door remote sensor/dash fuel-temperature gauges circuit. I don't need a class with specifications but I will love to have an idea of what happened. I was so confused, because for me a blew fuse will affect only the dedicated circuit, but this back-feeding to the AC circuit is crazy to me and I would never guess that the solution was very simple: just replacing a fuse.

From my part, I will be more careful and I will disconnect the battery negative before doing this and next electrical works.

I have a fairly related question. I had to jump my XG350 and accidentally switched the polarity when I understood the arrangement wrong on one of the vehicles and my radio and clock won't work now. I've checked all the fuses in the panel in the engine compartment and found nothing. I've also checked the audio fuse under the dash and that was fine. But it is so very difficult to get to the other fuses in that dash panel, so I'm wanting to figure out which other fuse might be related to the problem before I spend the excruciating hour it would take to pull every fuse to check. Any help would be greatly appreciated!

Scratch that--fixed it!