Technician a says that the battery must be in good condition and at least 75% charged to accurately test an alternator. technician b says that alternator output should be tested at idle. which technician is correct? a. technician a.
b. technician b.
c. both a and b.
d. neither a nor b.

Technician A

Explanation:

Technician A statement is correct as  

The battery is required to start the vehicle which, in effect, rotates the alternator at sufficient speed to keep the battery charged. This means if the battery is low it is not possible to start the vehicle and thus we are unable to test the alternator.  

That is the battery is pre-requisite to test the alternator. So the battery must be at least a 75 % charge to test the alternator.