Many Fords run what is called a "Smart charge" system,
Which in lay mans terms means the cars computer or ECU or PCM as Ford call it is responsible for the charging or not on the alternator output.
The PCM can decide to switch off the alternator at say start up then turn it on when it decides if conditions are right.
Net result of all this electrickery is any alternator/battery charging fault must start with a full diagnostic scan.
Preferably with Ford's diagnostic system.
It needs to be determined just when and how much charge the system is outputting.
Not the kind of thing most mechanics have come across.
Posted on Friday 12th of January 2018Don't understand this? Ask a question