I have a 2000 7.3 and have been having issues. truck would not start when it was delivered. Replaced the batteries. Rebuilt part of the fuse panel. Now battery light comes on and off. Checked the alternator and it is charging properly. Gauge shows it is charging as well. Now we are going to put in a new fuse panel.Any thoughts on this problem ? Thanks.
Check the 2/3 wire connector on the alternator, mine was bad and did those same things. 1 of those wires is the battery light. It goes from the alt to the fuse panel to the dash. The other I dont remember what it does. A new connector ($30 at ford) fixed my issues.
A long time Ford tech looked at the truck today and said the after market alternator was the problem. He said he has seen this problem on a lot of Ford trucks . He said to install a motorcraft alternator. We shall see.