High voltage Dart -67

Am I missing what your voltage problem is? I see in the title it states high voltage.
Give some more details for members to chime in for troubleshooting ideas and solutions.
It's currently loading over 16 volts
I read about cutting one wire that goes thru the bulkhead and run it thru a relay so I did that and the voltage went around 15,5 volt so it's still too high