Hey all, own a 2013 expedition. Had a new engine put in at 84,000 miles. Everything is working great except the battery light is on constantly. New battery, 2 different alternators, new pig tail. Computer says ecm. Ecm has been replaced. I’m thinking a possible bad ground somewhere but looking for other ideas if someone has any thanks
From what you say about the issue it seems there is a problem in the wiring to the alternator. I assume that the alternator is charging the battery as it should be. Is that correct? If so then I suggest you remove the small wires going to the alternator. Then start the engine, if the warning light wiring is okay then the light should not be on now. If it is still on then there is a ground on the lead for the warning light that ties to the alternator.
Has anyone checked the connection between the alternator and the battery. There should be a high amperage fusible link (some call them fuses) between the two and inside the underhood fuse block I would assume; although I hate to use the word assume…
Does the battery light stay on with the small plug in connector of the alternator wiring disconnected? It should not as it grounds through the alternator.