transmission Archives

The back-up lights are the next thing to wire in our customer’s 1967 Mustang project. We’re getting to the end of the switches that we need to wire to the MASTERCELL.

If you look at your configuration sheet, you will not see a dedicated output for back-up lights. Depending on the vintage of the car and the manufacturer, there may or may not be back-up lights on the car. We don’t dedicate an output to this but you can use any of the OPEN outputs on your rear POWERCELL.

This link will take you to the configuration sheet for the system that we are installing in this 1967 Mustang. This link will take you to our previous post in this series going through the details of the configuration sheet. You will see that there are several outputs that are labeled as OPEN on the configuration sheet. Depending on the version, you may have 4 to 6 OPEN outputs. OPEN means that there is no specific function assigned to the output. These can be used as generic outputs. You will note that the personality for these outputs is TRACK. That means that the output will track the switch. When the switch is on, the output is on. When the switch is off, the output is off. You can use OPEN outputs for things like amp triggers, extra lights, transmission cooler fans, secondary fuel pumps and back-up lights.

Output 5 on the rear POWERCELL is OPEN. This is the white wire coming from the B harness. The MASTERCELL input is the white wire with the red wire. This is input 2 on the MASTERCELL A input harness.

We previously connected the white wire from the rear POWERCELL to the back-up lights in the rear of the car. The customer is using the tail light assembly from Mustang Projects. You can read about that in this blog post. The white wire connects to the tail light assembly. Then the assembly needs to get connected to ground. Follow the instructions that came with your back-up lights for the exact wire colors.

Next, the MASTERCELL input wire needs to connect to a switch that closes when the transmission is in the reverse position. Our customer is using a Ford AOD transmission in this car. There is a dedicated connector on the driver’s side of the transmission. We connected to this connector in a previous post for the neutral-safety signal. We are going to connect to the same connector for the reverse signal.

Sketch of the Reverse/Neutral Safety Switch Connector on a Ford AOD Transmission

This diagram will show you which terminals on the Ford AOD transmission you need to connect to ground and to the MASTERCELL input harness.

Wiring diagram for Reverse/Neutral Safety switch on Ford AOD transmission

Terminal 1 on the transmission connector needs to get connected to ground. Terminal 2 needs to connect to the MASTERCELL input for the back-up lights. In our case, this is the white wire with the red tracer on the MASTERCELL A input harness. This link will take you to a PDF of this document.

When the transmission is in the reverse position, the switch makes a connection between terminals 1 and 2. This connects the MASTERCELL input to ground. When the MASTERCELL sees the input connect to ground, it sends a signal to the POWERCELL in the rear of the car to turn on the output that we have chosen for the back-up lights. When the transmission is taken out of reverse, the switch opens which disconnects the MASTERCELL input from ground. The MASTERCELL sees this change and sends a command to the POWERCELL to turn off the output that we have chosen for the back-up lights.

Most transmissions will have a set of contacts for a reverse switch. In other cases, there will be a switch in the shifter that will be made when the transmission is in the reverse position. Check the literature that came with your transmission or your shifter.

That’s it. Having a POWERCELL in the rear of the car makes wiring the back-up lights very easy. There is no extra wire to run to the back of the car. You are already using the existing POWERCELL to manage this.

Please contact our team with any questions about wiring with our Infinitybox system. You can contact a member of our technical support team by clicking this link.

A lot of people have seen a video from one of our customers starting his car remotely with an iPad. His iPad is connected to the inTOUCH NET module in his car. This lets him control everything including lights, windows, heat & A/C and locks. It also lets him start the car. Starting a car remotely can be very dangerous. If the car is started with the transmission in gear, it can launch the car forward potentially injuring, maiming or killing someone. In our Infinitybox system, there is a neutral safety switch input that must be wired before the engine will start. This is true for starting it with a keyed switch, our one-button start or remotely from inTOUCH NET.

Some people call these park-safety switches, clutch interlock switches or neutral safety switches. Regardless of what you call them, they are used to detect if it is safe to turn the starter. They either detect that the transmission is in park, the transmission is in neutral, the clutch pedal is depressed or your foot is on the brake. This is a standard input on all of our systems that must be wired correctly for the starter output to turn on.

The neutral safety input works like any other MASTERCELL input. It must be connected to ground to work. When you try to start the car, the MASTERCELL checks the state of the neutral safety input. If it is not grounded, the MASTERCELL will not let the POWERCELL turn on the starter output. The MASTERCELL must also see the neutral safety input change periodically. If the input is tied directly to ground or if the switch fails, it will not let the starter crank.

All safety switches essentially work the same way. If there is continuity through the switch then it is safe to start the engine. Most transmissions have switches built into them that close when it is in neutral or park. That is the case for our customer’s 1967 Mustang. They are using a Ford AOD transmission with the built in switch. In other cases, you may have a switch on your clutch pedal. When you press the clutch, this closes the switch. You wire the MASTERCELL input to one side of the switch and ground the other side. You can also have a switch built into your shifter. This switch is closed when the selector is in the park or neutral position.

If your car has none of the options above, you can wire your neutral safety input from the MASTERCELL to the brake pedal switch in parallel with your brake light input. When you step on the pedal, the MASTERCELL will see both the brake light input and the neutral safety input. The brake lights will turn on and the MASTERCELL will allow the starter to crank. You simply connect both MASTERCELL inputs to the same terminal on the brake pedal switch. This diagram will show you how to do this.

Image of wiring diagram showing how to use your brake pedal as a neutral safety switch

Going back to the Ford AOD transmission, there is a connector on the transmission for both the neutral safety and the reverse lights. We’ll talk about reverse lights in an upcoming post. This picture shows how to wire the MASTERCELL input for the neutral safety to the connector on the transmission.

Wiring diagram for Reverse/Neutral Safety switch on Ford AOD transmission

The neutral safety input from the MASTERCELL will connect to Terminal 2 on the connector. Terminal 1 will connect to ground. See our warnings in previous posts about good ground connections. When the transmission is in park or neutral, the switch closes. This connects the MASTERCELL input to ground. You can download a PDF of this wiring diagram by clicking this link.

Starting issues related to the neutral safety switch are probably our number 1 technical support call. Most guys just don’t read this in the manual. Your call will not start unless you have this MASTERCELL input wired properly. Please click on this link to contact our technical support team with questions.

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Back-Up Lights

Neutral Safety

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