Ford Model T Wiring Diagram - Coil Box, Commutator, Magneto & Headlight Wires

This document is an illustrated wiring reference for an early Ford Model T engine and ignition/lighting system, uploaded to accompany a 1909 Model T (the filename suggests it covers 1915-1918 models). It shows a labeled cutaway/pictorial drawing of the four-cylinder engine with the ignition coil box mounted at the left, callouts identifying the battery terminal, magneto terminal, lamp switch, switch-to-terminal wire, and magneto-to-coil wire. The coil box wires are color-coded: No. 1 Black, No. 2 Red, No. 3 Blue, No. 4 Green, and the same color code is repeated at the commutator (timer) at the front of the engine. The commutator wire assembly is identified as a 5-way cable, and the magneto contact is shown on the engine block. Spark plug wires No. 1 through No. 4 are labeled at the cylinder head, along with the horn, horn-to-switch wire, and horn-to-terminal wire. The lighting circuit shows two electric headlights connected by a lamp connecting wire, with the lamp wire grounded to the radiator support. A reader can learn the correct wire colors, routing, and grounding points for the Model T magneto ignition, horn, and headlight wiring.