Reverse Lockout Solenoid

A customer just sent us pictures showing how he wired a switch into his transmission shifter to control his reverse lockout solenoid.  He wanted to make sure that he couldn’t accidentally shift into reverse when he was in the upper gears.  By using our Infinitybox wiring system, he was able to easily control this solenoid.

Ed K. is building a 1968 Pro-Touring Mustang fastback.  He has transplanted a Coyote engine from a 2014 Mustang and mated it to a Tremec T56 6 speed transmission, feeding a Ford 9 inch rear end for the drivetrain.  He is using our 20-Circuit Kit with inLINK, inRESERVE and inMOTION to wire his car.

The Tremec transmission is outfitted with a solenoid lockout feature that further pre-loads an already compressed spring acting on the shift gate to prevent accidentally engaging reverse while downshifting from 6th gear to 5th gear, which would be catastrophic. In order to engage reverse, when desired, this solenoid must be energized to remove this extra spring pre-load. Typically, this solenoid is energized by a body controller when the car is moving at 5 miles per hour or less to allow a shift into reverse. Ed wanted a simpler way to engage this reverse lockout solenoid in his 1968 Mustang.

Ed modified the shift lever to add a microswitch to it.  When he pulls up on the shifter handle, the switch closes.  He can use this switch to control his reverse lockout solenoid.

Ed picked the OPEN output on his front POWERCELL to power his reverse lockout solenoid.  The OPEN outputs on your configuration sheet can be used for practically anything.  They are auxiliary outputs for any additional electrical accessories that you may have on your car.  Click on this link to learn more about OPEN outputs.

Ed connected this open POWERCELL output wire to the solenoid, then grounded the other side of the solenoid wiring.

Next, Ed found the MASTERCELL input that corresponds to the OPEN output that he used.  Your configuration sheet shows you which input and output wire colors go together.  Ed connected this MASTERCELL input to the normally open terminal on his shifter switch.  Then he connected the common terminal of the switch to ground.  When he pulls up on the reverse handle, the switch closes.  This connects the MASTERCELL input to ground.  The MASTERCELL sends a command to the front POWERCELL to turn on the output, which energizes the reverse lockout solenoid.  This pulls back the reverse gate, which lets him shift into reverse.  Here is a simple wiring diagram showing how this was connected.

Picture of simple schematic showing how to control a reverse lockout solenoid with the Infinitybox system.

Picture of simple schematic showing how to control a reverse lockout solenoid with the Infinitybox system.

Ed was able to wire his reverse lockout solenoid easily with our Infinitybox system.  He didn’t have to add any relays to his car to do this.  He was able to use the flexibility and expandability of our system to get what he needed in his car.

You can download a PDF version of this wiring diagram by clicking this link.

Click on this link to learn more about what the Infinitybox system can do for your restoration, street rod, resto-mod, kit car or pro-touring build.




Jeep CJ7 Wiring Series- inRESERVE Location

Over the next few videos, we’re going to continue our theme on good planning.  Specifically, we’re going to talk about picking the best locations for the major components that come with your Infinitybox system.  We’re installing our 20-Circuit Kit with inLINK and inRESERVE in our 1979 CJ7.  To get the most out of our install, we want to pick the best locations for the MASTERCELL, the front & rear POWERCELLs, the MEGA fuse holder and the inRESERVE solenoid.  We’ve broken this up into multiple, talking about what you need to consider for each part.  This video covers picking the best location for the main parts in the inRESERVE Active Battery Management System.

inRESERVE is our Active Battery Management System.  It is an accessory to our 20-Circuit Kit.  inRESERVE works with your MASTERCELL and POWERCELL to monitor your battery voltage and actively disconnect the battery if it gets too lot.  You can click here to get to another video that goes through inRESERVE in more detail.  There are two main parts of the inRESERVE Kit that need to be planned for in your install.  The first is the inRESERVE latching solenoid.  The second is the manual reset button.

The heart of the inRESERVE kit is a special latching solenoid.  It takes a pulse from a POWERCELL output to latch open, disconnecting all power from the battery to minimize battery drain.  The inRESERVE solenoid needs to be located between the positive terminal of your battery and the block of 4 MEGA fuses that distribute power to your POWERCELLs.  The best location that we found in our Jeep is right in front of the battery, under the hood.  We’ll mount this solenoid on the same plate as the MEGA fuses.

The location of the inRESERVE reset button is really important.  When inRESERVE does its job, it completely shuts down the Infinitybox system.  You need to be able to get to your reset button from outside of your car of truck.  If you have it inside and you have electric poppers, you won’t be able to access it to reset your system.  We’re going to mount our reset button next to the battery and the solenoid under the hood.  Check out the details in the video below.

This picture will show you schematically how the inRESERVE solenoid gets wired to the primary block of Mega fuses that comes with your 20-Circuit Kit.  You can download a PDF of this schematic by clicking this link.

This diagram will show you the overall relationship between the inRESERVE battery disconnect solenoid, the battery, the Mega fuse block and the 8-gauge power feeds that go to each of the POWERCELLs.  You can download a PDF copy of this diagram by clicking this link.

Infinitybox Jeep CJ7 Wiring Diagram- Cell Locations and Primary Power Routing

Infinitybox Jeep CJ7 Wiring Diagram- Cell Locations and Primary Power Routing

Keep watching for more in our 1979 Jeep CJ7 Install Series.

Be sure to subscribe to our YouTube channel and click the bell icon so you get notified when we post new videos in the series.

Click on this link to get to the main page for the 1979 Jeep CJ7 wiring project.  You can find all of the videos on one place there.  

You can also click here to contact our technical support team with any questions about your car or truck wiring project.  



Our inRESERVE Active Battery Management System is a great accessory for your 20-Circuit Kit.  As you add more and more electrical requirements to your car, the demand on the battery increases when the car is sitting idle.  inRESERVE continuously watches your battery voltage and safely disconnects the battery if it gets too low with your car is not being driven.  This keeps your battery from being deep cycled and always leaves enough charge in the battery so you can get started again.  Learn more about inRESERVE in this video.

You can add inRESERVE to your Infinitybox 20-Circuit Kit by clicking this link.

Click this link to get in touch with our technical team with any questions. 

Starter Motor

Next in our wiring series, it is time to wire the starter motor.  There are a few important things that need to be considered when you do this.  In this post, we are just talking about connecting the POWERCELL output to the starter solenoid.  In later posts, we will go through the details for wiring the ignition and starter switch.

There is a dedicated output on the front POWERCELL for the starter solenoid.  In most kits it is the light-blue wire, which is output 4 on the B connector.  When you turn on the MASTERCELL input for the starter, you get power on this starter wire.  This energizes the starter solenoid coil.

There are two main types of starter motors.  Some have the starter solenoid built into them.  Others rely on an external starter solenoid.  It takes hundreds of amperes to crank an engine.  Your battery is the source of this current.  It takes a special solenoid to repeatedly switch this high current.  A normal relay can’t carry this amount of current.  You need a solenoid.  This picture shows you the details of a typical starter motor with a built-in solenoid.

Drawing of the anatomy of a starter motor

Drawing of the anatomy of a starter motor

The starter solenoid gets a direct connection from the battery.  This will supply the starting current when you turn on the starter.  There is also a contact on the starter solenoid that connects to the starter output on the POWERCELL.  When you turn the key to the start position, battery voltage is applied to this start terminal.  This voltage does two things.  The solenoid pulls in which pushes the Bendix out to engage with the engine flywheel.  It also closes a large set of high-current contacts within the solenoid that lets current flow from the battery to the starter motor.  This current spins the motor, which turns the flywheel.

When you release the key from the start position, the battery voltage is removed from the start terminal on the solenoid.  This opens the contacts providing current to the motor, so the motor stops spinning.  Also, the Bendix retracts from the flywheel.

This picture shows a typical wiring diagram for a starter motor with a built-in solenoid.

Starter motor drawing showing different electrical connections

Starter motor drawing showing different electrical connections

The B terminal connects directly to the battery.  We’ll discuss this in more detail below.  The M terminal is internally connected to the windings on the starter motor.  The S terminal is what connects to the starter output on the POWERCELL.  When there is battery voltage from the POWERCELL on the S terminal, the solenoid engages.  The Bendix extends into the flywheel and the B terminal gets connected to the M terminal.  This provides the current to turn the starter motor.  The starter motor gets grounded to the chassis through its mounting plate to the engine block.

There are other starter motors that do not have the built-in solenoid.  They use a different mechanism to extend the pinion into the flywheel.  They rely on an external solenoid to switch the current to the starter motor.  This picture shows an example of an external solenoid.

Cole Hersee Solenoid

Cole Hersee Solenoid


This external solenoid is what switches the high-current for the starter motor.  One of the large terminals connects to the starter motor.  The other large terminal connects directly to the battery.  Again, we’re going to talk about this battery connection below.  One of the small terminals needs to get connected to ground.  The other small terminal needs to get connected to the starter output on the POWERCELL.  When the POWERCELL applies battery voltage to to the starter terminal, the solenoid closes and lets current flow to the starter motor, which turns the flywheel.

Now it is time to talk about the battery cable.  This is what supplies current from the battery to the starter motor.  At the instant you close the starter solenoid, the current flowing to the starter motor can be between 1,500 to 2,000 Amps.  Once the engine starts to turn, that current will drop down to 200 to 400-Amps.  You must make sure that you size this cable appropriately.  A lot of guys get cheap with their battery cables and go with smaller gauges.  This is a case where the bigger, the better.

We recommend using a 1/0 or 2/0 welding cable to connect the battery to the starter.  Smaller cables will result in voltage drop to the starter.  Voltage drop will lead to problems starting the engine.  Welding cable is much more flexible and easier to work with than typical battery cables.  It is easier to route through the car.  Please note that we do not include the battery cable or the required ring terminals in our kit.  You need to source these separately.

You also need to consider the grounds between the engine block and the chassis.  Whatever current flows to the starter has to return to the chassis.  You need to have good and large ground straps between the engine block.  The size of the ground cables must be equal or greater than the size of the cable you have feeding the starter.

Please click on this link to contact our team with questions about wiring the starter output on the POWERCELL in your 20-Circuit Kit.