I believe Ford used machine regulated alternators on early Zetecs. Your fault as described is a little odd but may be caused by a faulty onboard alternator regulator as clearly battery volts should be higher with engine running. Could you check battery voltage across terminals with multimeter with/without engine running and with/without headlamps on.
Thanks Richard
What are machine regulated alternators - is this the same as Smart Charging via the ECU?
I should be able to do those battery voltage checks on Wednesday, possibly Thursday.
I may even be able to use the Topdon to check the alternator - Although it claims to be able to test alternators I am not sure if it will give a valid answer because of the possible Smart Charging System. Hence the question re.Smart Charging
