Step by Step: How to connect a DC-DC Charger to your vehicle (with VIDEO)

Step by Step: How to connect a DC-DC Charger to your vehicle (with VIDEO)

Wagan Tech2/10/24

by Justin Gray

We’re going to go through the steps for a DC to DC charger installation. We will give you the basic steps and tools needed… It's important to note that vehicle engine compartments and their layouts are different, so each set up will require a slightly modified set-up. With that said, you’re still going to get the essential knowledge to get it done yourself.  So let's get started!

If you aren't sure what a DC to DC charger is, be sure to watch our other DC to DC charger Videos. Links at the bottom of this blog. 

Also, find out if your vehicle has a smart alternator prior to attempting installation. If unsure, contact your vehicle manufacturer’s local dealership.

Tools needed: 

  • Eye protection
  • Wire strippers
  • Electrical crimper
  • Electrical wire
  • Multi-connection battery terminal (optional)
  • Multimeter (optional)
  • Wire terminals (depending on set-up)
  • ANL fuses and fuse holders x3 

(you’ll need three 40A fuses for the 25A DC-DC Charger - if you have the 40A DC-DC Charger, you’ll need three 60A fuses and fuse holders)

Step one: Find the ideal mounting location for the DC-DC Charger. 

The unit is waterproof and sealed, but as with any electronic device, it is best to place it in a location that is away from heat, water, vibrations, etc.

Once you’ve found an appropriate mounting location, disconnect the starter battery’s negative cable - this is going to be the black cable with a (-) sign.

Next, let’s start running the wires. 

Here is the proper way to connect wires using the provided butt-splice connectors and heat-shrink tubing: 

  1. Slide the heat-shrink tubing over 1 wire.
  2. Strip the protective sheath from the wire with the wire strippers to expose the conductor strands inside - there should be approximately 3/8” of bare conductor strands exposed.
  3. Place the butt-splice connector over the bare conductor strands. Use the Wire crimpers to firmly press and lock the butt-splice connector onto the conductor strands. 
  4. Repeat the process on the remaining wire.
  5. Slide the heat-shrink tubing over the butt-splice connector and the wires. Use a heat-source to shrink the tubing. A heat gun is ideal, but a lighter can be used in its place if used carefully.

If you’re running a Solar Panel, connect the green wire from the DC-DC Charger to the Solar Panel positive input - be sure to add an ANL fuse inline on the wire. For this instance the Solar panel is 15 feet from the DC-DC Charger and we’re using the 25A DC-DC Charger… according to our chart, this wire needs to be 10AWG or greater and also needs a 40A ANL fuse.

Now let’s connect to the starter battery by connecting the yellow wire from the DC-DC Charger to the positive terminal on your main battery. Don’t forget to install the fuse on this wire too! 

This wire can be connected in several different ways:

  • You may be able to use the existing set-up by adding a ring terminal to the end of the wire connecting it to the battery clamp.
  • If you have side post terminals, you may need an adapter. 
  • You may also opt to get a Multi-connection battery terminal to make it easier to install this and future accessories. 

Next-up is the blue alternator trigger wire. If you have a smart alternator, you’ll need to connect the blue wire to the vehicle’s ignition source; if you don’t have a smart alternator, then you’ll just leave this wire open.

To connect the blue wire to the ignition, you’ll need to find a vehicle wire or fuse that only receives power when the ignition is on. If you’re proficient with a multimeter, you can easily find a source, otherwise you’ll need to consult the dealer.

Now we’re going to connect to the red Auxiliary battery. This procedure will be the same as the connection we made earlier to the starter battery and will depend on the terminal type located on the battery. As before, don’t forget to add a fuse on the positive wire between the battery and the DC-DC Charger’s red wire.

Are you running the Remote Monitor in your set-up? Now would be a good time to install it! If running it into the cab of the vehicle, find an access point through the firewall. 

I will often find an existing loom of wires that are already going through the firewall and run the cable alongside of them - usually there’s enough space to accommodate additional wires.

Once you’ve found the way into the cab, you’ll have to find a place to mount the remote; we like the ones custom made by solve function 

Most modern vehicles have an easy-to-locate grounding point within the engine compartment. Find a nice, solid, un-painted, ground location and run the black wire from the DC-DC Charger to this location. Due to the varying ground posts types, the type of wire-termination needed will vary too. In our set-up, we’re using a body-ground that is already present.

*Be sure to clean up the wires. Don't leave loose wires running around the engine compartment; make sure they are kept clear of moving parts and hot surfaces.

And there you go, we’re done! It’s time to program your DC-DC Charger to match your set-up and needs of the system. Take a look at our video on how-to program the DC-DC Charger so it is optimized for use with your system.

Do you have any questions or comments? Leave them below and we’ll answer them for you!




BLOG: What is a DC-CC Charger?

BLOG: Q&A: DC to DC Battery Chargers FAQ

PRODUCT: DC - DC Battery Charger 25A

PRODUCT:  DC - DC Battery Charger 40A

PRODUCT:  Digital Remote Interface

PRODUCT:  ANL Fuses (assorted capacities)

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