Ford Repair Questions? Ask a Mechanic for Answers ASAP
Thanks for coming to Just Answer to ask a question.
You have some possible sources here like wiring issues or poorly built aftermarket alternators not motorcraft brand. I beleive the concern is a none compatable alternator. By clicking here you can do this short and fairly easy ford pinpoint test. Below are the diagrams and some info on this to aid in diagnosing it with a volt ohm meter.