Yes, as far as I know it is just like coming right off the battery only triggered with the key and going through a fuse. Not running (key on) I get 12.+V. with it charging with my battery tender Jr. I get 13.3V. and running I get 14.+V. I think it is 14.7 Volts. Just Curious, why would you think that would not work. click link!That will tell me the volts , by tapping into that ?