Hi I am new here so I'm not sure if I'm posting this in the correct spot, but I'm having big electrical problems with my 2018 GMC Sierra 1500. it started about 1.5 weeks ago, I turned my truck on one cold morning(-15C) and my speakers were making crackling noises with no music coming out at all, no door chimes or signals either. I noticed my volts were around 15.5-16, but it never went over 16. the music would come back on when I turned the engine off and just had it on ACC mode. I called my mechanic and he told me it was probably my alternator, so I paid to Get that replaced, he returned it and nothing changed. still having the exact same problems. I called him again and he took it back in and looked at it some more. The speakers now crackle for the first 5ish minutes of the vehicle turning on, and then eventually smooth out as the volts settle down to around 14.3V. I put in all new speakers around the truck about 6 months ago, with an Amp and subwoofer, but I am just now experiencing problems with it. I tried taking the power cable off of the amp, and its still doing it to the door speakers and tweeters. I am now out $1100 and still having this issue, if ANYONE could give me some advice or something I could try that would be awesome,
Thanks!