High Voltage Alternator Issue Chevy Trailblazer/Silverado

I've been chasing a problem on my 2007 Chevy Trailblazer where at first start up it is over 15 volts and fluctuates as low as 12. Being old school, thought it was the voltage regulator on the alternator. Replaced the alternator and still had the problem. The battery was over 3 years old, so thought replacing the battery would fix the problem, but still would go up to 15.2 volts on start up. A friend of mine said these newer vehicles, the voltage is controlled by the computer. So, I was hoping my computer wasn't going bad. After a few years of research, I stumbled on battery sensors going bad in 2007 era Chevy Silverados and these battery sensors going bad. Decided to purchase a new GM battery sensor and see if it fixes my problem. Unhooked the negative battery cable from the battery, pushed the bolt through the battery end connector, slid the boot off the cable, unplugged and unwrapped the battery sensor from the cable and found the sensor wouldn't slide over the battery end connection. The ring hole on the battery sensor is 7/8" and the battery end connection is 1-1/8". Decided to shave the battery end connection down to 7/8" instead of cutting the factory cable and replacing with a universal end. Battery sensor slid right off. Replaced the battery sensor, taped down the sensor with wire harness tape the best I could (will have to take the battery completely out to make room to wrap the cable tightly with the wire harness tape), replaced the boot and put the bolt back in. Hooked everything back up and the voltage is now 14.2 when I crank it. Problem seems to be solved. Hope this helps someone. Thanks for watching!