Wiring Connections; Black Wire (Chassis Ground) - Crime Guard 328i2 Installation Manual

BLACK WIRE - (Ground): The function of the black wire is to supply
the system with (-)negative chassis ground.
Connect the Black wire to a clean solid chassis ground using a crimp-on
ring terminal. Scrape the metal surface to remove any rust, paint, grease, or
debris. Do not ground alarm to the vehicle's battery or dashboard screws.
Note: If the ground connection is insufficient, the system can find partial
ground through other connections. In this case the system may partially
function, possibly arming & disarming, but would otherwise operate
erratically giving the impression of being defective.
Warning: Do NOT ground the single black wire attached to the brain. This
is the system's antenna wire. Grounding the antenna wire will severely
affect the system's operating range.
Example #1: An existing machine-
threaded bolt that holds large structural
pieces of the dash frame to the vehicle's
framing structure may be used.
Self-Tapping Screw
"Star" Washer
Black Wire
Example #2 Grounding The Black Wire To Sheet Metal: Running the screw through
two layers of sheet metal allows more threads to contact the metal, which reduces the chances
of the screw to strip out or become loose. Grind the surface until the metal is shiny and clean.
-Avoid trying to drill through the spot welds, which are harder than the surrounding metal.

Wiring Connections

Black Wire
3
Ring Terminal