I have seen several photos of a black box on the firewall between wiper motor and air conditioning unit on the firewall. My car does not have this, can you tell me what that little black square box does and what it is called?

 

Without a pic I would have to guess voltage regulator.....Maybe someone has moved it or switched to a one wire alternator.

 

Circled image

 

Voltage regulator

 

Thank you. I appreciate the feedback.

 

The 1972 Cutlii used an external voltage regulator. If you car has been converted to a 12SI alternator with internal regulator, that original external regulator is not needed.

 

1972 PIM

 

Thank you so much for the diagram.