make sure it is securely mounted.
When checking the alternator, check that it is securely fastened. Check that all wires are undamaged and securely fastened. Check that the belt is in good condition and the belt deflection is between 1/2 inch and 3/4 inch.
B make sure that some of the wires are securely fastened.
C make sure that some of the wires are undamaged.
D make sure that belt deflection is at least one inch.