I took the time today to research the 914 wiring diagrams and find the annoying connection that leaves my tail light on after I turn off the ignition switch.
If you remove the front dashboard cover and look under the steering column, you should see two connectors. Remove the right one as shown above.
On the rear of the connector should be three wires colored grey, grey/red and grey/black. Snip the grey one and seal BOTH ends with heat-shrink tubing or end-wire crimp. After cutting this wire, you will no longer have the feature that turns on your tail lights when you leave the turn signal lever activated. It's important to protect both ends because one is tied directly to the 12V battery through a fuse and the other gets 12V when you turn the tail lights on. You don't want either of these touching any part of the grounded chassis.
I really hope I'll never kill my 12V battery again by leaving on the turn signal. Other critical functions (like the emergency flashers) still work fine.
Okay, back to driving and finishing up the open-source Civic project. Best wishes to all.