Complete 2013 Nissan Altima Speaker Wiring Guide and Color Codes
Begin by locating the main amplifier unit beneath the driver’s seat–pinouts differ slightly between factory and aftermarket setups. Factory harnesses use a 16-pin AWM 20277 connector, with dedicated channels for front and rear outputs. Left and right door tweeters share a 2.2Ω impedance with separate high-pass filters; bypassing these may cause distortion above 12kHz. Rear deck speakers (6×9-inch) require 4Ω stable amplification, while subwoofer pre-outs are typically low-level RCA, though some trims include a factory line-out converter embedded in the head unit.
Identify the color-coded wiring:
- Solid blue – amplifier turn-on signal
- Blue with white stripe – antenna motor control
- Green/Green-black – rear left/right (±) pairs
- Grey/Grey-black – front right (±)
- White/White-black – front left (±)
- Purple/Purple-black – subwoofer (+/-), if equipped
Ground wires (black/brown) must attach to the chassis using 12-gauge crimp connectors to avoid voltage drops. Factory harnesses often include 10A fuses inline with power leads–replace with 15A for aftermarket upgrades without exceeding OEM fuse ratings.
For aftermarket integration, disconnect the negative battery terminal before splicing. Use T-tap connectors or solder and heat-shrink tubing for non-destructive modifications. Front door speakers connect via harness clips behind the kick panel; remove the lower dash trim by prying the four plastic clips with a trim tool. Rear speaker wires route through the B-pillar trim–remove the rear seat cushion (press tabs near the front edge) to access the trunk harness bundle.
Test connections with a multimeter set to 20V DC before powering the system. Factory door tweeters expect 5.5W RMS; exceeding 8W risks voice coil damage. If installing a DSP, route RCA cables away from OEM CAN bus wires to prevent interference. For vehicles with BOSE or Rockford Fosgate systems, retain the factory EQ module–removing it triggers a check audio system warning on the instrument cluster.
Audio System Connection Guide for 2013 Sedans
Begin by identifying the vehicle’s 12-pin harness connector behind the stereo unit–pin #1 (left front +), #2 (left front ground), #3 (right front +), #4 (right front ground), #5 (left rear +), #6 (left rear ground), #7 (right rear +), and #8 (right rear ground). Use a multimeter to verify continuity; a resistance below 4 ohms confirms proper contact. Factory harnesses often include a pink (constant 12V), yellow (switched 12V), and black (chassis ground)–ensure these match aftermarket adapters like Metra 70-1761 or Scosche SNIBM2C.
Troubleshooting Common Issues
- Reverse polarity on door drivers causes phase cancellation–swap ± wires if sound cuts out at high volume.
- Aftermarket amps require a remote turn-on wire (blue/white strip) from the head unit’s connector; tap into pin #9 to avoid battery drain.
- Rear fill channels (pins #10–#12) often share grounds; isolate them with a separate 16-gauge wire to prevent interference.
- Factory tweeters use a high-pass filter (typically 80Hz); bypass it only if replacing with component speakers rated for full-range output.
Always secure connections with heat-shrink tubing or crimp caps–loose terminals degrade audio clarity over time. For OEM replacement parts, consult Nissan’s service manual (page 21-5) for speaker impedance specs (4Ω standard).
Finding Audio Cable Pathways in Door Assemblies
Begin by disconnecting the vehicle’s negative battery terminal to prevent short circuits. Use a trim removal tool to pry off the interior door handle bezel–apply steady pressure at the lower edge to release clips without snapping them. The panel is secured with ten plastic retainers and three screws: two behind the handle and one near the door pull.
Remove the moisture barrier sheet carefully; it’s adhered with a light sealant that can tear if pulled too quickly. Peel it from the top down to avoid stretching the material. Behind this layer, the sound component harness becomes visible–bundle colors differ by side (front driver side: gray/black, passenger side: gray/orange). Trace these to their termination points at the factory module.
- Driver door bundles terminate at a six-pin connector near the window regulator
- Passenger door runs directly into the kick panel harness junction
- Rear units (if equipped) follow a separate channel beneath the rear seat mounts
Use a multimeter on continuity mode to verify connections; factory harnesses often include resistive elements for fade-in circuitry. Probe the terminals at both ends–impedance should read between 3.8 and 4.2 ohms for mid-range components. Low or inconsistent readings indicate corrosion, requiring terminal cleaning with electrical contact spray.
Reassembly requires aligning the moisture barrier’s original edges to prevent water ingress. Press firmly around the perimeter to reactivate the adhesive seal. Door panel clips re-engage with a distinct snap–if resistance occurs, reposition before applying force. Test functionality by reconnecting the battery and verifying all channels through an audio head unit scan.
For vehicles with upgraded sound systems, note that aftermarket harnesses often reroute through additional loom conduits. Locate these behind the door jamb cover panel; they typically use 16-gauge twisted pairs with color-coded sleeves matching the OEM scheme. Secure any exposed runs with automotive-grade zip ties to prevent rattle interference.
Distinguishing Front and Rear Audio Channel Cable Colors During Upgrades
Locate the harness connector behind the door panels or beneath the dashboard–front channels typically terminate near the head unit or kick panels, while rear outputs extend toward the parcel shelf or trunk bulkhead. Use a multimeter set to 200Ω continuity mode: touch one probe to a chassis ground and the other to each cable; factory harnesses mark positive leads with solid colors (gray, purple, light blue) and negative with matching stripes (gray/black, purple/black, light blue/black). Cross-reference the pinout labels on the vehicle’s OEM amplifier if present–front left signals pair gray wires, front right match purple, rear left correspond with light blue, and rear right align with green.
| Channel Position | Positive Lead | Negative Lead |
|---|---|---|
| Driver-side front | Gray | Gray/Black |
| Passenger-side front | Purple | Purple/Black |
| Left rear | Light Blue | Light Blue/Black |
| Right rear | Green | Green/Black |
Verify connections by disconnecting the factory harness adapter before powering up aftermarket components–avoid back-feeding voltage into tweeters which often share front channel outputs through inline capacitors. Rear channels may include separate harness branches for subwoofer outputs; identify these by thicker gauge cables or dedicated RCA jacks if equipped.
Step-by-Step Guide to Testing Audio Output Lines with a Multimeter
Set your multimeter to the 200-ohm resistance setting before probing any connections. Locate the harness terminals behind the door panel or under the dashboard where the factory sound system links terminate–these are typically 10–16-gauge cables, color-coded for left, right, and ground channels.
Touch the multimeter probes to each pair of exposed leads while the vehicle’s ignition is off. A reading between 2 and 8 ohms confirms continuity; anything above 10 ohms or below 1 ohm signals corrosion, fraying, or a short. Check both positive and negative leads separately–ground reference should register near zero resistance to the chassis.
If readings fluctuate or show an open circuit, strip ¼ inch of insulation from the suspect conductor and retest directly on the copper strand. Bare metal surfaces must be clean; oxidation often mimics a failed circuit. Apply dielectric grease after confirming conductivity to prevent future interference.
Switch the multimeter to AC voltage mode (200 mV range) and turn the audio system on, playing a 1 kHz test tone at moderate volume. Probe the terminals again: expect 1–5 volts RMS on active channels. Silence or drastically lower readings pinpoint amplification issues or severed connections upstream.
For bridged or amplified outputs, increase the multimeter’s AC range to 20 volts. High-power amplifier outputs may reach 20–30 volts RMS–readings outside this range suggest incorrect impedance matching or faulty signal processing. Measure both channels simultaneously to detect phase cancellation.
Inspect connectors for bent pins, melted plastic, or greenish residue indicating moisture intrusion. Re-seat suspect plugs firmly; vibrations can loosen factory crimps over time. If replacing connectors, use gold-plated contacts rated for 20 amperes to handle dynamic current surges.
After repairs, solder joints instead of twisting or taping vulnerable splices. Use heat-shrink tubing rated for automotive temperatures (-40°C to 125°C). Secure loomed cables away from moving parts–seat tracks, pedals, steering columns–to prevent chafing.
Recheck all measurements with adjusted volume levels, bass frequencies, and fade/balance controls. Stable readings across all settings confirm circuit integrity; intermittent drops necessitate inspecting upstream components like the head unit or signal distribution block.
Troubleshooting Common Issues with Factory Audio System Links
Start by verifying ground connections–corrosion on the chassis attachment point disrupts signal integrity more often than failed amplifiers. Use a multimeter to measure continuity between the grounding terminal and the vehicle’s metal frame; readings above 0.5 ohms indicate oxidation requiring cleaning with a wire brush and dielectric grease. Check for loose harness pins at the back of the head unit, particularly the orange illumination wire that frequently separates causing intermittent volume drops.
Inspecting Power Delivery and Signal Pathways
If distortion persists at high volumes, probe the 12V constant and accessory lines with the ignition on–voltage below 11.8V suggests a weak battery or alternator. Examine the RCA output jacks on aftermarket adapters for bent contacts, as partial engagement mimics blown channels. Replace any spliced speaker cables exceeding 18 AWG, as thinner wires introduce resistance leading to muddy bass reproduction.