Mazda diagrams use standard abbreviations. Knowing these is half the battle:
These share a common ground point in the tailgate. The diagram will show ground point G-09 (inside the tailgate trim). Rust and corrosion here kill both circuits simultaneously. mazda premacy wiring diagram
Without the diagram, you risk shorting out the Body Control Module (BCM) or damaging the new aftermarket unit. Mazda diagrams use standard abbreviations
The diagram will show: Battery → Headlight Relay (coil controlled by headlight switch) → Fuse (e.g., 15A, labeled HEAD LH) → Bulb → Ground. mazda premacy wiring diagram