So I finally looked up what this button did in my 1963 Ford Thunderbird user manual. It turns out the white button was placed in the parking brake bulb location. I had purchased the electronics needed to make a button operational from the brake light location. The intent was to have a button that would manually turn on the electric fans pulling air through the radiator. After some consideration I decided I don’t want to take the risk of the fans not being on during higher temperatures and just have it on all the time.