Fuel Pump

Now it is time to wire the fuel pump to the POWERCELL in our 1967 Mustang project.  This is the last major output that needs to be wired in.  In our next series of posts, we will be talking about wiring the switches to the MASTERCELL.

There are lots of different kinds of electric fuel pumps for cars and trucks.  Primarily, they fall into two categories: in-tank and in-line.  These are pretty self-explanatory.  In-tank fuel pumps are mounted in the fuel tank.  In-line fuel pumps are installed somewhere in the fuel line running between the tank and the engine.  Our customer is using an Aeromotive 325 Stealth In-Tank Pump for this project.

Aeromotive Stealth Fuel Pump

Aeromotive Stealth Fuel Pump

Just like everything else in your car, thoroughly read and understand the manual that came with your fuel pump before you start this part of the install.  Remember that you are playing with Gasoline.

Wiring for the fuel pump is pretty simple.  The fuel pump needs battery power and ground.  The battery power is going to come from a POWERCELL output.  The ground connection is going to be made locally to the chassis.

This Aeromotive pump has two wires: red and black.  Black is ground and that is going to connect to the chassis.  Remember how important good ground connections are.  Make sure that you have a reliable metal-to-metal connection between your ground wire and the chassis.

The red wire is power.  This is going to connect to a POWERCELL output.  In most of our configurations, this power comes from output 10 on the rear POWERCELL.  This is the tan wire on the A connector.  The advantage of using our system to power the fuel pump is that the pump gets connected to the local POWERCELL.  The fuse and relay for that pump are built into the POWERCELL.  If you have a POWERCELL mounted in the rear of the car, the power wire going to the pump is very short.

We need to make a few comments about current draw.  Take a good look at the manual or specifications for your fuel pump.  You have 25-amps of steady-state current draw to work with on each POWERCELL output.  Aeromotive publishes great graphs in their manuals that show current draw and fuel flow versus pressure.  At the highest flow rate and highest pressure, this pump draws about 16-amps.  This is well below the 25-amp capacity of a single POWERCELL output.

In some cases, you need to provide power to the fuel level sender in the tank.  If yours needs to be powered, you can splice off the fuel pump output on the POWERCELL.  It is a good time to wire sender power if needed while you’re wiring power to the pump.

That’s it for wiring the fuel pump output.  We’ll talk about wiring the fuel pump trigger to the MASTERCELL in upcoming blog posts.  Click on this link to contact us with questions or comments.


Now it is time to connect the POWERCELL outputs to your loads in the car.  When we talk about loads, we refer to the things that you need to power to make the car work.  These include your headlights, turn signals, ignition systems, starter solenoids, fuel pumps, cooling fans, horns, lights, etc.  All of these loads are going to the connect to each POWERCELL output to get their switched battery power.

This post is going to cover the basics of wiring the POWERCELL outputs.  We will publish several specific posts that will go through the details of how to wire your turn signal outputs, wiring your ignition and starter, wiring cooling fans and other loads.

The automotive electrical system uses a grounded chassis.  This means that each load gets its switched power from some power distribution device.  In your case, it is your POWERCELL.  Current flows from the POWERCELL to the load.  To complete the circuit, the load needs to get connected to ground, which is typically your chassis.  The chassis is connected to the negative post of the battery.  This is how the circuit is completed in your system.

Another thing to remember about your Infinitybox system is that the switches connect to the MASTERCELL.  Your loads connect to the POWERCELLs.  There is no connection between the switch and the load.  That connection comes from a data command sent from the MASTERCELL to the POWERCELLs.  When you turn on a switch, the MASTERCELL tells the POWERCELL to turn on an output.

Your kit includes an A & B output harness for each POWERCELL.  If you have our 10-Circuit Kit with one POWERCELL, you have one each of the A & B harnesses.  If you have our 20-Circuit Kit with two POWERCELLs, you will have two of each.

This picture shows you the POWERCELL A output harness.  It has the wires for outputs 6 through 10.

POWERCELL A Output Harness

POWERCELL A Output Harness

This picture shows you the POWERCELL B output harness.  It has the wires for outputs 1 through 5.

POWERCELL B Output Harness

POWERCELL B Output Harness

Yes, we get that it seems that the A & B designations are reversed for these harnesses.  That designation came from the original layout of the POWERCELLs from our early beginnings.  These designations have stuck and changing over a decade of documentation would be tough.

Please note that the A & B connectors are interchangeable in the POWERCELL output sockets.  A lot of initial problem calls that we get from customers come from the fact that they have these harnesses reversed.  Make sure that you are plugging the correct harness into the correct socket.  The manual that came with your kit shows you the correct orientation.  This picture also shows which connector socket is A & B.

Illustration of Infinitybox POWERCELL labeling output connectors

Illustration of Infinitybox POWERCELL labeling output connectors

Once you get the connectors plugged into the correct sockets, you need to properly ground the POWERCELLs.  Each of of the output harnesses have a black wire.  Both of these black wires need to get grounded to the chassis.  This is to properly ground the electronics in the POWERCELL.  Make sure that you have a good metal-to-metal connection between these ground wires and the chassis.  You must make sure that you remove all dirt, rust, oil, grease, paint and powder coating from this connection.

Next, it is time to start connecting the POWERCELL output wires to the loads in the car.  Remember that your configuration sheet is your road map to do this.  You can review our previous blog post about the configuration sheet as a refresher by clicking this link.  The configuration sheet is going to identify the specific POWERCELL output wire by color for each load in the car.

You are going to run the POWERCELL output to the load.  From there you must connect the POWERCELL output wire to the wiring on your light, fan, horn, fuel pump, etc.  There are many different ways to do this.  People will argue advantages of one method over another.  If done correctly with the right tools, they are all good methods.

One of the easiest ways is to butt splice the POWERCELL output wire to the wire on your load.  For example, you cooling fan will probably have two wires coming from the motor housing.  You can use a butt splice connector to connect the POWERCELL output wire to the wire on the fan motor.  This picture shows an example of a butt-splice.

Picture showing example of splicing wires in our 1967 Mustang Install of the Infinitybox wiring system.

Picture showing example of splicing wires in our 1967 Mustang Install of the Infinitybox wiring system.

The team at Waytek Wire have a great post on their blog called “Splice Connectors 101”.  In this article, they walk you through the basics of splicing wires together.  Click here to read this article. 

What is important is that you use the correct crimp tool and you properly seal the joint.  This seal can be done with heat shrink tubing or you can use butt crimp connectors that already have a heat-shrink jacket over them.  Companies like Waytek and Del City are great sources for the right tools and materials.

Another option is to solder the wires together.  A lot of customers swear by this method or a combination of butt-splicing and soldering.  The advantage is that you get a metallurgical connection between the copper strands of both wires.  Some will argue that this is stronger and more reliable than a pure mechanical crimp of a butt-splice.  Just like the butt-splice mentioned above, this joint must be sealed preferably with heat shrink.  The only warning with soldering is that if too much solder is applied to the joint, it can wick up the strands of the wire flowing away from the joint.  This wicking can make the wire more rigid and susceptible to fatiguing if the joint is stressed mechanically.  Just watch the amount of solder that you are applying to the joint.

The last is to put connectors on both ends of the connection.  This is the most time consuming and costly, but it has advantages down the road if you need to remove the load for maintenance.  There are many different options for connection systems.  Deutsch connectors are very popular in racing.  They are rugged, durable and proven.  Delphi Weatherpack connectors are another option.  They have been proven in the field for decades and are a cost effective option.  You can purchase Weatherpack kits from many different sources that include the proper tools to crimp the terminals.  Here is an example of a Weatherpack kit that includes the tool.

If the POWERCELL output harnesses are not long enough, you can easily extend them using any of the connection methods mentioned above.  You must make sure that you use the right size of wire and the right insulation type.  We use 14-AWG wire for all of the POWERCELL outputs.  This will carry 32-amps continuously, which is very conservative for most aftermarket and racing applications.  We use wire with TXL insulation.  This is a cross-linked wire designed for the automotive environment.  It is oil, dirt, chemical and abrasion resistant.  You can source extra 14-AWG TXL wire at this link.  We can also create custom harness lengths.  Contact our sales team for details.

Just a few last comments about wiring the POWERCELL outputs.  Stay away from Home Depot.  We say this as a joke but it is important.  The same materials that you’d use to wire a house have no place in the car.  That means no wire nuts, extension cords or electrical tape to make connections.  Use only tools and materials that are designed to handle the automotive environment in your car.

Keep watching for the next posts that will detail wiring POWERCELL outputs to some of the specific systems in your car.  If you have any questions, please click on this link to contact our team.

Output Voltage

We get a lot of questions about how the POWERCELL outputs work on our Infinitybox systems.  Here are answers to the two most common questions.

First, a lot of customers ask if we do anything to modify the voltage on the outputs on the POWERCELL when they are on.  The answer is that we do nothing.  The POWERCELL is going to put out whatever voltage it gets in from the battery.  If the battery is low, the POWERCELL is going to output the same low output voltage.  If the alternator is charging, the POWERCELL is going to output the same voltage as the battery is seeing.

The second question that we get from customers is why there is voltage on the POWERCELL output pins when the output is off.  This voltage is part of our diagnostics on the POWERCELL.  When you wire your car with Infinitybox, we give you powerful diagnostic capabilities that you can’t get from a traditional wiring harness.  For our output detection circuit, there is a small amount of current that leaks out of the POWERCELL output.  This is less than 100 micro-amps.  If you have everything connected properly, this leakage current flows through the fuse, through he output connector, through the wire, through the load (light, fan, ECU, etc.) to ground.  If there is a break anywhere in this chain, this leakage current flows back into the LED on the POWERCELL output, causing it to glow dimly.  This is your indicator to check the fuse, look for a break in your harness, check your ground or check for a problem in your load like a burned out light bulb.

If you were to measure the open circuit voltage on a POWERCELL output with a multimeter, you would measure about 2.8-volts.  This is absolutely normal.  Click on this link to download our diagnostics manual to learn more about this.  

If you have any questions about this post or anything else related to wiring your car with our Infinitybox system, give our tech team a call at (847) 232-1991.