Fog Lamps is correct
The power feed yellow 3-way connector near the fuse box ( alternate spot is to battery side of starter relay) goes to the C.B. from the other terminal of the CB the Light Blue/Black stripe wire runs to the Fog Lamp Switch
...once turned on ...power then flows through the other 2 wires.
Grey, and black
The gray wire runs to a connector at the firewall and continues to the lamps
The black wire goes to the headlight switch (see loose wire with bullet connector) to illuminate the tail-lights.
Here is my diagram

Here is Ford's
Top left hand corner
http://hammar.dyndns.org/~djhamma/wiring/1966/66exter.jpg
The power feed yellow 3-way connector near the fuse box ( alternate spot is to battery side of starter relay) goes to the C.B. from the other terminal of the CB the Light Blue/Black stripe wire runs to the Fog Lamp Switch
...once turned on ...power then flows through the other 2 wires.
Grey, and black
The gray wire runs to a connector at the firewall and continues to the lamps
The black wire goes to the headlight switch (see loose wire with bullet connector) to illuminate the tail-lights.
Here is my diagram

Here is Ford's
Top left hand corner
http://hammar.dyndns.org/~djhamma/wiring/1966/66exter.jpg