Where to Locate PTO Input Signal

    Audience Fleet Admin
    Applies To PTO Cable, Vehicle Gateway

     

    Introduction

    The Motive (formerly Keeptruckin) PTO AUX cable (Cable-5005) captures PTO (power take-off) activity. This helps in obtaining accurate usage data, such as information on location and duration of PTO use, classifying idling due to PTO, and providing alerts during unsafe scenarios where PTO is engaged on a moving vehicle.

    This article gives additional details on where to locate the PTO input signal on your vehicle.

    Note: This is currently available to customers on the Pro and Enterprise subscription package.

     

    Procedure

    • To install Cable-5005 (AUX/PTO Cable), we first need to find the input signal on the vehicle, which we will use to monitor the on/off status of the PTO equipment. 
    • This is a voltage source that needs to be between 2.2V and 48V (steady-state) in the “ON” position, and 0V in the “OFF” position in order to be compatible with our device.
    • Depending on the PTO type, the input voltage source we will splice into to monitor the on/off state of the equipment will vary.
    • A common voltage source is the “PTO Engaged” switch or PTO indicator light on the dash.

    Below are two methods to help you in this process.

    Method 1: Using the in-cab ‘PTO Engaged' switch

    A common PTO input source is the in-cab “PTO Engaged’ operator switch. The switch should be clearly labeled and within reach of the driver inside the cab. The goal is to get the PTO signal from this switching circuit.

    The switch will be either electric or air-powered.

    Electric switches

    • If the vehicle has an electric PTO switch, the best place to obtain the switching source is from the indicator light (example of a “PTO Engaged” indicator light shown below). This light is usually near or on the switch itself. 
    • Access the back of the indicator light, identify each wire for the indicator light, and use a voltmeter to confirm which is being switched when the PTO equipment is “on”, either the low-side (“Active-LOW” or “ground switching”) or the high-side (“Active-HIGH” or “high-switching”).
    • 12V high-side wires are usually red, while ground-side low-side wires are usually black.
    • If the light is Active-HIGH, splice it into that to use as the PTO input (“AUX”) signal.
    • If the light is switched-LOW, then modify the circuit to provide a switched-HIGH signal.
    • The voltmeter should show 0V across the light when the PTO is OFF and can show anywhere from 2.4V to 48V when the PTO is ON (12V is typical).

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    In cases where the PTO input source is a negative voltage, a relay will also have to be used. Motive suggests using a Bosch relay (p/n: 0986AH0611) in most cases, but it will vary by install.

    Air switches

    • If the unit uses an air switch, we will need to locate or install an air pressure switch/sensor to obtain a signal for the Vehicle Gateway auxiliary circuit.

    electric_switch4.jpeg

    • The air pressure switch must be configured as a Normally Open Switch “N.O.” (meaning that the switch is in the open position when there is no pressure in the airline).
    • One side of the N.O. switch must have +12V on one side (usually from the fuse panel or battery). The other side will be going to the Vehicle Gateway (ELD) Auxiliary circuit.
    • When the PTO switch is pressed, air pressure causes the switch to close and send voltage to the AUX circuit on Cable-5005.

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    Method 2: Use a PTO input source from the equipment itself

    • There may be no suitable PTO input source in the cab. A common reason for this is that the PTO signal may be fully integrated into the vehicle via the CAN bus. In this case, there is no steady-state analog voltage that can be used.
    • It's also possible that all the controls for the PTO equipment are outside of the cab.
    • In either case, you will have to find a usable PTO input signal outside the cab. Likely, this will still be an LED or switch located at the PTO controls.
    • Using the same strategies in Method 1, find the PTO input source outside the cab and run the wires back into the cab to connect to Cable-5005.

    Connect the PTO input signal to Cable-5005

    After locating where the PTO input signal will be taken from, we will need to run a wire from that device to Cable-5005.

    The pictures below show an example of a wire being run from the PTO input source (secured with a ring terminal) to Cable-5005 (soldered together).

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