Mechman GM Alternator Voltage Boost Harness 1.5V Increase for Lithium — Big Jeff Audio Dealer Platform
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  • Enhanced Voltage Output: Increase your alternator's voltage by 1.5 volts with this harness, specifically designed for alternators equipped with a GM 4 pin regulator.
  • Temperature-Dependent Performance: Tested on Mechman Alternators, this harness yields just over 16 volts in warm temperatures, with output varying based on ambient temperature.
  • Compatibility Assurance: Ensure your added components, such as car audio amplifiers, can handle the higher voltage to prevent damage or protect mode activation.
  • Easy Installation: Connect the yellow wire to an ignition-switched 12V+ source and the blue wire to the alternator's threaded output stud for straightforward setup.
  • Versatile Application: Suitable for engine swap applications lacking stock alternator harnesses, allowing alternator control through a 12V switched connection.

Mechman GM Alternator Voltage Boost Harness 1.5V Increase for Lithium Batteries

This Listing includes:

  • (1) P101-L-3 Voltage Boost harness

Elevate your alternator's performance with the Voltage Boost Harness for GM 4 Pin Regulators. Designed to increase voltage output by 1.5 volts, this harness is compatible with alternators featuring a GM 4 pin regulator, such as Mechman Alternators. Tested to produce just over 16 volts in warm temperatures, its output varies with ambient temperature. It's essential to ensure that connected components, like car audio amplifiers, can withstand the increased voltage to prevent potential damage. Simple installation involves connecting the yellow wire to an ignition-switched 12V+ source and the blue wire to the alternator's threaded output stud. Ideal for engine swap applications lacking stock alternator harnesses, this harness offers a convenient means of alternator control via a 12V switched connection.


  • Increases alternator voltage by 1.5 volts

  • Tested on Mechman Alternators for reliable performance

  • Temperature-dependent output with variation based on ambient temperature

  • Compatibility with added components like car audio amplifiers

  • Easy installation with connection to ignition-switched 12V+ source and alternator output stud


  • Compatibility: GM 4 pin regulators

  • Voltage Increase: 1.5 volts

  • Output Voltage: Just over 16 volts in warm temperatures

  • Wire Colors: Yellow (ignition-switched 12V+), Blue (alternator output stud)

  • Application: Engine swap applications, alternator control via 12V switched connection

    ** NOTE: This unit is NOT FOR USE ON STANDARD 12V AGM BATTERIES. This module will increase the charging voltage by 1.5 Volt and WILL DAMAGE AGM batteries. Please check with your Lithium battery manufacturer to verify the proper charging voltage before installing this module! Not all Lithium type chemistries require higher voltage charging!**

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