This is for the Spark in "B" mode which will support the 2005-2015 Toyota Tacoma

If you have a 2007-2021 Toyota Tundra or 2008-2017 Toyota Sequoia, please go to our other listing for the Spark in "C" mode

If you have a 2008-2015 Toytoa Landcruiser or a 2008-2015 Lexus LX570, please go to our other listing for the Spark in "A" mode


VoltageBoosterPRO is a user adjustable diode modification with an inline fuse that allows you to safely increase your alternator voltage to optimize your AGM battery charging. AGM batteries (Optima, Odyssey, Northstar) are undercharged when used with your factory Denso alternator. Traditional flooded acid batteries at charged at ~13.8v, but AGM batteries often specify a charging voltage of 14.5+. Undercharging your AGM battery reduces battery lifespan and available charge capacity. The VoltageBoosterPRO lets you do a diode modification so that you can increase your alternator voltage output to charge your AGM battery a higher voltage while also maintaining a fuse for that circuit! This is perfect for your deep cycle AGM applications. 

We HIGHLY recommend not doing the DIY GM Diode mod, which when done REMOVES the safety fuse of that circuit. The GM Diode is NOT a fuse. Shorting a fuse using a plain diode is not a great idea. A team of engineers spent years designing the electrical system of your truck. If you do any diode mod, please make sure you have a fuse in that circuit! Otherwise if you have a short circuit, you may have a full battery amperage fire in your engine bay!

With this mod, you retain the fuse on that circuit, in a clean, easily removable package.

The “Low” mode provides ~0.4-0.5V of increased alternator voltage. The “High” mode is ~0.8-1.0V.

Each unit is made in San Antonio, Texas, USA. 


One Minute Installation:

  1. Locate the ALT-S fuse in the engine fuse box.
  2. Remove it and place into the Voltage Booster PRO
  3. Place the Voltage Booster PRO into the removed fuse location