There are two special harnesses used in 1965 for fog lamps, the under dash and the under hood. Fog lamps were included in the GT package and in the deluxe interior package. Both packages had a 66 type 5 dial instrument cluster. The deluxe interior would have a "B" after the body type on the door data plate, 63B, 65B and 76B. Check the instrument cluster first.
Jim