How to Replace the Ignition Switch on a 1978 Chevy Truck Nov 07, 2017Install a new switch by fitting the activator rod, mounting the new ignition switch with the screws and plugging in the wiring harness. Install the dimmer switch with the shared screw. Remount the column, attach the battery cables, and check the Related searches for 1978 chevy ignition switch wiring chevy ignition switch wiring diagram1955 chevy ignition switch wiring1957 chevy ignition switch wiring1956 chevy ignition switch wiring56 chevy ignition switch wiringchevy ignition switch diagramchevrolet ignition switch wiring diagram1955 chevy ignition switch diagram