Here's a cut and paste some links to other threads about '73 wiring.
Field circuit branches off of the ignition run circuit
Field Circuit shown in this post.
'73 Duster Cluster photos in this thread
Cluster fun.
There are two power supplies for the car.
Power flows from whichever one can supply at the higher voltage.
- Battery can supply power at approximately 12.5 Volts.
- Alternator will supply power at approximately 14 Volts.
Power distribution
The output wires from the battery and alternator are joined at a welded splice under the dash.
That welded splice is also a junction to feed the main circuits:
- Key switch (wire J1)
- Fuse box (fuses that are always hot) (wire Q3)
- Headlight switch power for headlights (wire L1)
View attachment 1716150457
Dome light, parking and marker lights, brake lights, horn, all get power directly through the fuse box's hot buss.
Windshield wiper switch gets power
only when the key is in accessory or run position.
Heater fan, Radio, Reverse lights, and Turn signals
only when the key is in accessory or run position.
On 1973 models, the heater switch, reverse lights, and radio share a fuse and wire circuit to the turn signal flasher.
Please note the ammeter is in the battery circuit. it shows current flowing into or out of the battery. Nothing else.
