This lighthouse once had an elevated catwalk leading out to it. One book I have says that the lighthouse was never manned. I cannot confirm or deny this. Look for a better description / history to come.
I received this information from J. I. Moyna Jr.
The lighthouse listed as the north pier light was never "manned" and used to have a catwalk for use during sever weather. The foghorn used to be operated by an air compressor which one could hear when standing close to the structure...one could tell when the next "bellow" of the deep and penetrating sound was coming. The old sound and system has been replaced with something less than loud and penetrating sometime in the early eighties.
As to your listing of the "secondary light", this is incorrectly identified as being on the North pier as one can see from the photo. In reality, this "secondary light" is called the South Pier Light and flashes Red to denote the opening between the two piers for boat passage. This is followed by two additional inner piers (stub-piers) inside the outer piers which showed the channel passage beside the Coast Guard station and onward into the Betsie Bay where the South shore held two "slips" for docking the Ann Arbor car-ferries...which terminated in 1982.
Directions: In the Town of Frankfort, follow SR-115 until it changes into SR-22 (Forest Ave). Follow this to the water. Then make a right onto 1st Ave and followed that to a parking area. From here, you can see the Frankfort North Breakwater Lighthouse.View more Frankfort North Breakwater Lighthouse pictures