So I just installed my alternater and I get no voltage from the alternator and a code that says P1638 - Generator F-Terminal Circuit. Thats it! Any idea whats going on, bad alternator or something on the car. I tested the output cable to the battery and its only showing 11 volts which i would assume is from the battery. Last night while I had the batter out of the car I wanted to get my cd's outta the changer so I hooked up the 12 amp battery charger and that gave me enough just to get the cd's out of the changer. Could I have ****ed up something or is the alternator just bad.