Description

The Speedhut 2-5/8" 4K RPM Diesel Tachometer (L25-TC6-LEG) is a vital monitoring tool designed specifically for diesel engines. Compatible with various diesel RPM signal types—including alternator terminals (‘R’ or ‘W’), crank sensors, and magnetic pulse sensors—this gauge provides highly accurate readings up to 4000 RPM. Its compact 2-5/8 inch size and 2.68-inch (68mm) mounting hole make it adaptable to most dashboards. It includes power and signal wiring harnesses and a programming button for easy calibration and LED feature setup. Although it lacks an internal shift light, the clear display and dependable performance make it a key component for maintaining optimal engine function.

KEY FEATURES AND BENEFITS:

• Diesel compatibility: Works with signals from alternator ‘R’ or ‘W’ terminals, crank sensors, or magnetic pulse sensors.
• Clear RPM range: Measures engine speed precisely from 0 to 4000 RPM.
• Compact form factor: 2-5/8 inch size fits a variety of dashboard configurations.
• Simple installation: Comes with necessary wiring harnesses for signal and power/lighting.
• LED calibration support: Programming button included for LED-lit configuration and calibration.

SPECIFICATIONS:

• Gauge Type: Tachometer
• Signal Type: Diesel (alternator with an ‘R’ or ‘W’ terminal, crank sensor signal, magnetic pulse sensor)
• Range: 0 – 4000 RPM
• Size: 2 5/8 inch
• Hole Size: 2.68 inches (68mm)
• Internal Shift Light: No
• Ships With:
• 3 ft Power & Lighting Harness – for LED Lit Gauges and Clocks
• Wiring Harness (2-Wire Cable)
• Gauge Programming Button (For LED-Lit gauges)

HOW TO USE:

1. Mount the Gauge: Secure the tachometer in a 2.68" (68mm) diameter hole using the provided spin ring.
2. Connect Power and Lighting:
   • Red wire to +12V power source
   • Black wire to ground
   • White wire to +12V dash lighting source (optional)
3. Connect Signal Wire: Use the 2-Wire Cable to connect to the engine’s RPM signal (alternator ‘R’/‘W’ terminal, crank sensor, or magnetic pulse sensor).
4. Initial Calibration:
   • Turn ignition ON without starting the engine.
   • Press and hold the programming button while turning the ignition OFF and ON again.
   • Start the engine. The needle should point to approx. 1000 RPM.
   • Hold the button to adjust the needle to your engine’s actual idle RPM.
   • Release the button once set. The gauge will return to 0 and then back to calibrated RPM to save the setting.
5. Further Calibration (If Needed): Repeat the process at different RPMs for accuracy across the full range.

BENEFITS OF USING THE SPEEDHUT 2-5/8" 4K RPM DIESEL TACHOMETER (L25-TC6-LEG):

• Provides accurate real-time RPM data crucial for maintaining diesel engine health.
• Helps prevent over-revving and potential engine damage.
• Improves fuel efficiency and driving control, especially with manual transmissions.
• Compatible with various signal sources for flexibility across vehicle models.
• Easy installation and calibration make it user-friendly.

FEATURES:

• Reads signals from alternator ‘R’/‘W’ terminals, crank sensors, or magnetic pulse sensors.
• Displays RPM clearly up to 4000 RPM.
• Compact 2-5/8 inch design fits most dashboards.
• Standard 2.68" (68mm) mounting hole requirement.
• Includes 2-wire signal cable for diesel RPM input.
• Power and lighting harness for LED illumination is included.
• Programming button enables easy calibration.
• Designed for long-term performance in demanding automotive conditions.