1. Checking current intensity

NOTE To remove the cover (1) (positioned on the positive battery terminal), act gently using a screwdriver in the position shown by the arrow, until the fixing pins come out.

1. Checking current intensity

• Fit the ammeter pliers on the alternator cable/junction unit
• start up the engine and let it run at between 3000 and 4000 rpm;
• switch on all the available consumers;
• measure the maximum current intensity supplied on the multimeter display.

If this value is more than 5A below the recommended figure, overhaul the alternator.

2. Checking voltage

• Place the multimeter probes in contact with the battery terminals;
• start up the engine and let it run at between 3000 and 4000 rpm;
• gradually switch on several consumers until the absorbtion is about half the maximum load.

Under these circumstances the voltage reading should be between the maximum and minimum values (see diagrams) depending on the ambient temperature of the electronic regulator (alternator).

Diagram A refers to an RT 121A electronic regulator which is incorporated in M. Marelli alternators, whilst diagram B refers to the EL 14V 4C electronic regulator which is incorporated in Bosch alternators.