I started a 'simplified' breakout of the lighting diagram for the car, but hope that breaking this into 3 pieces is a bit clearer. Specifically, here is the "key off" lighting diagram. Its a bit strange that most accessories in the Goose (windows and radio) operate without a key in the car, but that most of the lighting does NOT work unless the key is "on"...And this even applies to 2 of the courtesy lights (the one in the trunk, the other in the engine bay. don't adjust your set, your bulb is not bad---but even though those 2 lamps have their own switches, in fact the car ignition must be ON and the parking lights switched ON for those lamps to operate---and since you do not dare turn the key to ON without actually running the car, this means that the car must be running to light up !
Fuse #8 supplies power to all the lamps that operate when the key is OFF. The courtesy lamp on the rear bulkhead turns on when either a door is open or when the 3rd toggle switch is turned on. The lamps in the doors only turn on when the doors are opened.
The emergency blinkers do operate anytime the right most toggle switch (#7) is flipped up. The toggle switch alternates between the 'stalk' and the emergency circuit; when in the emergency circuit, the Sipea A72103 relay (used for many years on Fiats, for example) is energized, and forces voltage (tied at the Mamut connector blocks near the steering column) to the lamps at the 4 corners of the car...
(the fine print is that the headlamps are Also turned on even when the ignition is OFF, sourced by fuse F7 and turned on by the stalk on the steering column...I suppose DeTomaso was worried that customers would turn on their trunk light while unloading their groceries in the dark and then drain their battery overnight, so left these tied to the Key switch...but the Flash circuit was un-switched because it had the return spring...)