Black Chassis Ground Wire
Page 6
Wiring Connections - 5 Wire Connector
Chassis
Ground
Black Wire
The Black wire's function is to supply chassis ground to the CPU (Central Processing Unit or control module) for the security system's operation. We
recommend that this wire be connected before any of the security system's other wires.
CONNECTION: If you are using an Omega Research and Development Quick Interconnect Harness, ground for the Black wire may be provided from an
existing ground circuit within the vehicle or the Black wire may have a ring terminal already attached. A Quick Interconnect Harness is an adapter wiring harness
which plugs into an existing pair of the vehicle's connectors, with circuits needed for the security system branching off to a connector which plugs into the
system's CPU. The Quick Interconnect Harness allows an incredibly quick, accurate and clean installation. If ground is not provided through the Quick
Interconnect Harness, follow these steps:
Using the correct sized soldered or crimp-on ring terminal, securely connect the Black wire to the metal structure of the vehicle, preferably using an existing
machine-threaded fastener. The battery's negative post is a very poor choice for a grounding point due to the differences in the CPU and vehicle wire and terminal
sizes, and because of the very corrosive environment around the battery. Make sure that the Black wire's ring terminal has contact with bright, clean metal. If
necessary, scrape any paint, rust or grease away from the connection point until the metal is bright and clean. The security system's CPU should be given its
own grounding point (a dedicated ground). Never consider simply splicing the CPU Black wire into an existing "ground" wire, and avoid grounding to sheet
metal unless absolutely necessary.
Grounding The Black Wire To An Existing Bolt.
Security System
CPU
Use an existing machine-threaded
bolt that holds large structural
pieces of the dash frame to the
vehicle's framing structure.
Black Wire
Troubleshooting Tip: If the Black wire has a
poor ground connection, the system can find par-
tial ground through the wires that are connected to
other circuits, but the system will not function cor-
rectly, making you think that you have a defective
CPU. One example of this is when the system is
armed, but the siren sounds with a low volume. The
CPU is trying to ground itself through the siren in-
stead of through its normal Black wire, which
causes the low siren output. The system can par-
tially operate when the Black wire is not properly
grounded, so you would never suspect a poor ground
wire connection. In some cases the security system
could arm and disarm properly -but not function
correctly otherwise.
