Direct plug in solid state replacement, no modifications needed. We highly suggest considering not purchasing this unit and invest in the all inclusive unit. All of the original sequential components in the trunk of your Cougar are mechanical and will in time fail. It is much more cost efficient to buy the all inclusive unit than to purchase them one by one as they fail.
*NOTE* Need help diagnosing a Cougar turn signal problem? Victor Yarberry is the world's most knowledgeable expert on the subject. Vic has owned Cougars since the 1970's and is the designer of all of our solid state sequential systems. There is no question he cannot answer! Here is a link to a great source of information on the subject.