My wife's '87 wagon has suffered a chronic problem with the battery gradually draining down over a period of days, having to be recharged overnight once a week or so. The battery light has been glowing faintly most of the time, occasionally going out. I picked a new looking replacement alternator out of the boneyard today and put it on. The voltage at the battery was measuring around 12.3 or so on the old alternator. When I put the new one on, it showed about the same. It finally dawned on me to run a jumper wire from the battery to the field terminal on the back of the alternator. That turned off the light and kicked the voltage up to 13+ volts. I assume the wire that energizes the field is broken somewhere but I don't know where the thing runs behind the dash. Can anyone help, or tell me where to run a new wire. For the moment, I put an additional wire from the field terminal to a 12 volt source at the fuse box, assuming that I'd need to run a new wire into that area to have the charging system operating properly.