Harness: HRN-CW03K3 (3 wires without ECM)

3-wire harness for vehicles without ECM. One wire for Ground, one for Ignition, and the other for a power source.

Geotab Document: https://www.geotab.com/documentation/hrn-cw03k3/

There are three connection wires when using the HRN-CW03S3 harness:

Black Wire

• The "Ground" wire, which should be connected to a known good chassis ground. Yellow Wire The constant power supply wire (12V or 24V) which should be connected to a genuine battery source (under voltage at all times). The fuse size is 5A.

Yellow Wire

• The ignition detection wire, which should be connected to a genuine ignition source (under voltage when the key is in the ON position and running, without voltage when the key is off). The fuse size is 5A. 

Red Wire

• The constant power supply wire (12V or 24V) which should be connected to a genuine battery source (under voltage at all times). The fuse size is 5A.

✱ NOTE: The red and yellow wires must be connected to a source with a fuse, or the user must install the fuses.