Hello again, to my knowledge there was not a alternator in a 81 Cad that was regulated by the computor, they were not that advanced at that time in public automobiles. The alt has an internal regulator like all the other GM alts. For peace of mind, and for a check before you go thru the work of installing it, Take it to your local auto parts store and have it tested, (Autozone) the test is free and it will tell you for sure wheather I am correct, am if it is any good. Hope this helps....Chb46
