Join Date: Sep 2000
Location: Washington, Michigan USA
The backup light switch is mounted on top of the steering column, just rearward of the trim cover at the firewall; it will have a pink and a light green wire in the connector (pink is power feed, green goes to the lamps). The switch is operated by a tube inside the column, which is moved by the lever on the engine side of the column that's connected to the linkage and bellcrank that goes back to the reverse lever on the transmission.
The two purple wires you found spliced together are the "start" circuit from the ignition switch to energize the starter solenoid; sounds like someone bypassed the clutch safety switch.
The bulb sockets in the front valance panel are supposed to be double-contact, for dual-filament bulbs; if they're single-contact, someone changed them.
'69 Z28 Fathom Green