I have a 2011 Chevy Silverado 5.3L pickup...having some issues...recently the headlights started to flicker, then it went to turning my signal light whether it be left or right, when engaging my brakes and also turning my high beams on the truck would almost shut down...radio would go off, rpms would drop then go back up lights on dash would go crazy! I drove it straight to the shop they put it on their machine (or whatever the fudge they do) and it gave no codes as to something wrong so therefore they told me there was notta, nothing, zilch wrong with my truck! But it’s back....headlights are back to flickering...and I’m certain it will go wacky back to high beams turn signal brake pedal stuff again...what is a girl to do when they say nothing is wrong with your truck because no codes showed up so it is just fine? WTF? It is dangerous when it goes crazy and rpms drop lights are going wacko and I’m driving down the turnpike doing 80! Need some input guys...