Hi I have a 2015 GMC Sierra, My alternator went out about a week ago so I changed it out. A couple days later the one they sold me went out also so I went and got another one. This has happened 2 more times. Is there odds that I have bad luck and have gotten bad alternators because they are rebuilt or could something be causing it to go bad? I have looked up and seen the computer could cause a failed alternator but nothing else is wrong with the truck. No engine light, no bad idle, nothing else just my voltage meter dropping and when I get the alternator tested they tell me it has a bad regulator.