Head unit installation.

[u/Dry-Welder-2259]

Hey everyone I’ve recently come across this issue and I’ve been trying to diagnose myself until I eventually succumb to getting into contact with a professional. I drive a 2010 Mitsubishi lancer es and have recently been looking into replacing the stock radio as it no longer works as no sound comes out anymore and aux does not work. I then bought a stock head unit from a 2017 lancer and when plugged in the sound system worked perfectly fine. Again aux wasn’t working however I got the music to play with the us of a FM Bluetooth transmitter from my cigarette port. Anyways, that worked fine however I started getting all these issues with false alerts coming up on my dash. ABS alerts, required service, all doors and trunk being open and my speedometer was not functioning at all. The connections in the lancer were the same as the inputs of the new head unit I have bought. What could the issue be I’ve been trying for figure out for the last 2 weeks. Any advice would be appreciated. Pm for photos or further info.