Start with the factory harness located behind the rear bumper on the driver’s side. Disconnect the vehicle battery before touching any terminals to prevent shorts. Identify the existing seven-pin.

Start by locating the underhood fuse block near the driver’s side strut tower. Pin B9 on the 24-pin gray connector delivers constant 12V to the vehicle’s computer–confirm continuity with.

If your GM truck’s factory-infotainment requires modification or repair, the OEM harness pinout provides exact connections without guesswork. Locate the 24-pin gray connector behind the center stack–pins 1 through.

For immediate troubleshooting, reference the fusebox schematic (under-hood) labeled positions F4 (20A) for the ignition system and F5 (10A) for the powertrain control module. These are the most common.

Start by locating the main fuse box under the hood–this is the origin point for most engine compartment connections. The left-side bulkhead plug (C1) handles critical sensors: MAP, throttle.

Begin troubleshooting by locating the C1001 connector under the dash near the steering column. Pinouts follow this sequence: red (battery constant), pink (ignition feed), purple/white stripe (accessory), and yellow.

To troubleshoot or upgrade the sound installation in your late-model pickup, begin by locating the primary harness behind the dashboard cluster. The main power feed is typically a yellow.