Hello, I have read you findings on the chrysler 2.7 charging issue. The ground wires at g103. Great find. I have 05 sebring 2.7 with charging issue. Done a desire of the grounds. Keep finding the black wire from alternator having voltage while car is running. With only key on them no voltage on this site. As soon as I start the car the black and green wire as well as the battery wire show 12.3 volts and all 3 wires drop as battery goes dead. Why would I see voltage on black wire? This is 3rd alternator on car. The original I’m not sure what was wrong with it because my cousin just changed it and battery thinking it would fix charging issue. I cut the black wire loose at the alternator and for sure alternator is out putting battery voltage on this wire. Any ideas why. No voltage with key on just while engine running. Battery light never goes out. tried new even also. If I take this wire to ground alternator produces 14.6 volts constant. note: battery light on dash on constantly. Turn on headlights battery does drain faster. only fault codes are for all four oxygen sensors. No other codes present. I have now unhooked all then to assure no short from those. Same issue. Thank you.
The most likely cause of your problem will be the same G103 issue. The reason you find power on the black/tan wire with the engine running is due to the positive voltage being sent from the PCM to the alternator on the green wire. Without a ground on the black/tan wire that power signal will show up on the wire. The oxygen sensor codes are likely being caused by the same problem.