Description
Product Introduction
The Woodward 37331-01 is a 3-gauge dashboard kit containing one 3-3/8″ speedometer and two 3-3/8″ quad gauges. It leverages NVU’s Phoenix Direct Drive technology, meaning only the speedo needs 12 Vdc power to chain signal to the secondary units.
This black-face Woodward 37331-01 provides a modern tech look compared to the beige variants. The OLED trip window updates at 10 Hz. Typical sweep settling time hits <1.2 seconds from cold start.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Kit Composition | 1x Speedometer, 2x Quad Gauges (Oil/Fuel/Water/Volts) |
| Gauge Diameter | 3-3/8 in (85 mm) |
| Outer Diameter | 3-11/16 in (94 mm) |
| Speed Range | 0-140 mph (0-240 kph programmable) |
| Tach Range (Quad) | 0-8000 RPM (separate input per gauge) |
| Oil Pressure Range | 0-100 psi |
| Fuel Level | Programmable (0-90Ω / 240-33Ω) |
| Water Temp Range | 100-250 °F (verify with OEM datasheet) |
| Face Color | Black |
| Graphics | White / Wraparound Deco |
| Pointer Color | Red |
| Bezel | Polished stainless steel |
| Lens | Domed glass |
| Wiring | NVU Direct Drive (Daisy-chain ports) |
Woodward 47371-01
Quality Control Process (Engineer’s Perspective)
- Incoming Verification: Cross-check the NVU Woodward 37331-01 serials on all three 85 mm housings against the bill of lading. Inspect the domed glass for optical distortion or trapped lint under the bezel.
- Live Functional Test: Energize the speedo at 12 Vdc. Inject 60 Hz to the tach leads on both quads. All needles must sweep full scale; check OLED segments for dead pixels during the self-test sweep.
- Electrical Parameter Test: Sweep a pot across the fuel sender pins on the secondary quad using a Fluke 115. Verify the ADC tracking stays within 2% of the primary gauge—daisy-chain sync errors show here.
- Firmware Verification: Initiate the one-mile calibration via the remote button. Photograph the OLED confirming the PPM count locked—well, technically it supports push-button config, but only on firmware v3.2+.
- Final QC & Packaging: Slot each gauge into die-cut anti-static foam inserts. Coil the Direct Drive jumpers loosely. Apply a “QC Passed – 24hr Burn-in” label with the date before sealing the master carton.
Replacement Pitfall Guide
❗ Daisy-Chain Order: The Woodward 37331-01 requires a specific signal flow. Speedo Out goes to Quad 1 In, Quad 1 Out goes to Quad 2 In. Reversing the quads breaks the data link.
❗ Hole Pattern Alignment: Three 3-3/8″ holes need precise 120 mm center-to-center spacing. Off by 2 mm and the bezels touch—mock up the panel with a drill template first.
❗ Shared Sensor Grounds: Both quads share a common sensor ground plane on the speedo. Ground loops from mixed-case senders (e.g., isolated oil sender touching block) cause crosstalk on fuel readings.
❗ Power Budget: Driving two quads plus the speedo pulls ~150 mA at 12 Vdc. Ensure your fused supply has 20% headroom; voltage dip below 11.5 Vdc causes needle chatter at idle.
❗ ESD to OLED: The display drivers on all three units are static-sensitive. In dry shop environments, discharge to the chassis ground before handling the connectors—though your mileage may vary on humidity control.
Keep these in mind and you’ll cut 90% of rework time.
Woodward 47371-01
Compatibility Matrix & Benchmarks
- Woodward 37331-01 → Woodward 37331-02 : Direct — Face color swap (Black vs Beige)
- Woodward 37331-01 → Woodward 37204-01 : Needs Adaptation — Same tech, but 37204 is a 2-gauge kit
- Woodward 37331-01 → AutoMeter 4797 : Incompatible — Wiring harness and sender logic differ
- Sweep Response: < 1.2 seconds (0-140 mph step change)
- Signal Input Range: 2,000 to 40,000 PPM (Speedo), 0.5-333 Hz (Tach)
- Daisy-Chain Load: < 100 mA total draw on the slave ports
