Volts lower with car running .

[bpman1234]

So i gave the scanmaster its own ground to the battery. got it up to 12.8 orso gonna keep going to see if i can get it up morem no pun intended

 

[earlbrown]

The scanmaster reports the voltage the ECM tells it. Has nothing to do with the voltage going into the scanmaster.

 

[bpman1234]

So replaced the ignition switch the one down on the steering column did not make a difference . but when i replaced the fuse and it went up to 13.7. 13.8 and thats the best i got it up to read .one of you guys mentioned it so i did it and that made the biggest difference.thanks all you guys.