I have a 96 p38, i have a mysterious battery drain but i think i have rectified it. Now i think i have a charging problem. When the car is running at idle, the voltage at the alternator is 14.07v, but the voltage at the small alternator wire that goes to the becm is only 13.56v. Is that wire supposed to have voltage at that level or should it be higher? Please advise. Thanks!