I tried the Voltage last night and it stayed at 11.7- I also took the plug out of the back of the Alternator and it only has one blue wire in it? Is that Normal? When I started the car with out it in the battery light stayed off then came back on once I put it in. Pep Boys tested it again and they said both are good. Could it be the plug that inserts in the back of the Alternator? I have pictures but cant figure out how to really put them up.