My battery started giving me trouble about 2 weeks ago (needing a jump, struggle to start, etc.). As a result, I purchased a new battery 5 days ago and got it installed a day later. After the battery was installed 4 days ago, my truck has been starting up and running perfectly until today.
Today, I was on my way to work and my 2018 GMC Sierra completely shut off while I was driving on the highway at about 65 mph. The engine shut off, the screens went blank, the horn stopped working and the gauges stayed in the same position (ex. The speedometer stayed at 65).
When I popped the hood open, my negative connection was loose, but nothing happened when I tighten it. A friend offered to give me a jump but only the caution lights came on. We left the cables connected for at least 20 minutes but still nothing.
Any thoughts about this?