Description
Product Introduction
The Woodward 37204-02 is a 2-gauge dashboard kit featuring a 3-3/8″ speedometer and a 3-3/8″ quad gauge. It uses NVU’s Phoenix Direct Drive technology to simplify wiring—just plug into the port on the back of the driver gauge.
This beige-face variant offers period-correct styling distinct from the 37204-01 black-face version. The quad gauge reads oil pressure (0-100 psi), fuel level, water temp, and volts. Needle sweep settles within 1% accuracy after the one-mile calibration drive.
Woodward 47371-01
Key Technical Specifications
- Kit Composition: 1x Speedometer, 1x Quad Gauge (Oil/Fuel/Water/Volts)
- Gauge Diameter: 3-3/8 in (85 mm)
- Speed Range: 0-140 mph
- Tach Range (Quad): 0-8000 RPM (via separate tach input)
- Oil Pressure Range: 0-100 psi
- Fuel Level: Programmable (0-90Ω / 240-33Ω selectable)
- Water Temp Range: 100-260 °F (verify with OEM datasheet)
- Face Color: Beige
- Graphics: Black / Wraparound Deco
- Pointer Color: Red
- Bezel: Polished stainless steel
- Lens: Domed glass
- Wiring System: NVU Direct Drive (Daisy-chain capable)
Quality Control Process (Engineer’s Perspective)
- Incoming Verification: Match the serial stickers on both gauge backs to the NVU packing list. Inspect the third terminal block area on the speedo for cold solder joints or excess flux.
- Live Functional Test: Power up at 12 Vdc. Inject a 100 Hz square wave to the tach input. Both gauges must sweep full scale and return without mechanical binding at the stops.
- Electrical Parameter Test: Use a Fluke 115 to sweep the fuel sender simulator (0-90Ω). Check for linear resistance drop across the harness pins—anything over 0.5 Ω variance flags a harness defect.
- Firmware Verification: Trigger the one-mile learn mode via the remote button. Watch the odometer window (or needle flicker) to confirm the MCU latched the new pulse-per-mile count.
- Final QC & Packaging: Bag each gauge in anti-static foam. Seal the Direct Drive harness separately. Apply a QC Passed sticker with the date before boxing—though your mileage may vary on batch labels.
Replacement Pitfall Guide
❗ Direct Drive Orientation: The Woodward 37204-02 uses a specific master/slave configuration. Plugging the quad gauge into the speedo’s out-port is correct; reversing them kills the data link.
❗ Sender Ohm Range: The fuel gauge defaults to 0-90Ω. Connecting a 240-33Ω GM sender without reprogramming the button shows empty when full. Hold the button for 5s to toggle ranges.
❗ Tach Signal Voltage: This unit auto-senses 12 V coil or 5 V PCM signals. However, feeding a noisy MSD box output without the inline filter (supplied) causes needle flutter at high RPM.
❗ Hole Size Tolerance: 3-3/8″ is 85 mm, but cheap hole saws often cut 86 mm. The bezel overlap is only 3 mm; a loose hole lets light bleed behind the face at night.
❗ ESD During Cal: The calibration button ties to the logic chip. Discharge static before pressing—winter shop air here in Taiyuan gets bone dry, and a zap through the button traces is common.
Keep these in mind and you’ll cut 90% of rework time.
Woodward 47371-01
Compatibility Matrix & Benchmarks
- Woodward 37204-02 → Woodward 37204-01 : Direct — Face color swap (Beige vs Black)
- Woodward 37204-02 → Individual 3-3/8″ Gauges : Needs Adaptation — Requires separate power runs (no Direct Drive)
- Woodward 37204-02 → 4-3/8″ Quadzilla (37157-02) : Incompatible — Requires dashboard redrill to larger holes
- Sweep Response: < 1.2 seconds (0-140 mph step change)
- Signal Input Stability: 2,000 to 40,000 PPM (Speedo), 0.5-333 Hz (Tach)
