When you plan to install an alcohol interlock in a commercial vehicle, the first items people look at are the vehicle's voltage and the device's input voltage. An interlock is a device that controls whether the vehicle can start based on the result of the driver blowing into a handset. The DATECH AF-i1 consists of a breathalyzer handset and a control box that serves as the central processing unit, connected through the vehicle wiring.
So whether the voltage figures match is the starting point of the installation review, but it does not on its own lead to the conclusion that the device can be installed in that vehicle. Commercial vehicles with the same model name can differ in ignition method, add-on electrical equipment, and the space where the device will go. Before installation, check the current specs of the device to be installed side by side with the actual vehicle configuration, and after installation, record what was tested, so you reduce confusion during later maintenance or vehicle changes.
Compare the input voltage together with the device version
DATECH's official AF-i1 product page gives an input voltage of 8.5V minimum to 48V maximum. This figure is an important reference to compare with the nominal voltage of the vehicle to be fitted, but you should not directly apply figures from an old catalog or materials for another version as the conditions for the product currently supplied.
When reviewing, first settle the version of the AF-i1 to be installed and the spec sheet that applies to that product. A good next step is to check the power configuration and the connection points in the vehicle documents and pass that information to the installer. If figures or descriptions differ between documents, rather than choosing whichever range looks wider, first sort out which document is current for the product actually supplied.
Look at the start-control target and existing equipment together
The control box connects to the vehicle and performs start control according to the breath test result. So even if the voltage matches, you need to review separately the vehicle's start-control configuration and the point where the interlock will connect. If the vehicle already has a digital tachograph or other electrical equipment, it is better to confirm from the vehicle management records which equipment is connected where, rather than just listing equipment names.
Being told that the device has been installed in the same model before does not substitute for this vehicle's suitability either. The actual configuration can differ depending on options, add-on equipment, and maintenance history. The installer sets the connection points and test scope based on each vehicle's documents, and the fleet manager can contribute to the installation review the information held by whoever manages the existing equipment.
| Item to check | What to collect before installation | Judgment after checking |
|---|---|---|
| Power conditions | The vehicle's power configuration and the current specs of the device to be fitted | Use the input voltage comparison as the starting data for the installation review |
| Start-control configuration | The vehicle's ignition method and connection points | Review separately whether connection is possible for each vehicle |
| Existing electrical equipment | Equipment already connected and wiring-related documents | Decide the installation scope after confirming how the devices relate |
| Mounting environment | Where the handset and control box will go and protection conditions | Compare with the device specs and the conditions inside the vehicle |
The items in the table are not meant to create a lot of paperwork. For example, if you start installation without knowing about existing equipment, you may need to recheck the actual connections related to start control even though the voltage comparison is done. Conversely, if you collect the necessary vehicle documents before installation, it is easier to separate what has been confirmed from what needs further review.
Choose the mounting location with use and inspection in mind
The handset is the device the driver uses for breath testing, and the control box is the unit that handles the vehicle connection and processing. Where these two components go in the vehicle is not just a question of whether there is empty space. Whether the driver can use the handset properly, and whether the components can be reached when inspection or device checks are needed after installation, are also conditions to review.
The official AF-i1 guidance gives an operating temperature of -40 to 85℃. However, this figure alone does not make every mounting location inside a particular vehicle suitable. You can consider preparing photos or location information so the installer can judge, comparing the protection of the intended location and the vehicle-specific environment with the spec sheet and installation conditions.
A review sequence in a hypothetical case
As a hypothetical example, consider a logistics fleet manager who wants to schedule installation right away because the vehicle's nominal voltage falls within the input voltage range given for the AF-i1. However, the vehicle has existing electrical equipment, and the management records do not describe in enough detail how that equipment is connected. The fact observed here is that "the voltage figures were compared, but the start-control configuration and the relationship with existing equipment were not confirmed."
It is more accurate to interpret this situation not as an installation feasibility verdict being complete but as information still being needed for the vehicle-specific review. A possible action is to pass the vehicle's ignition method, existing equipment information, desired mounting location, and the version of the device to be installed to the installer and set the scope of the review. Do not choose to check things by connecting wiring yourself or changing protective devices.
The completion criterion in this case is not simply a note that the voltage is within range. The criterion is that the installation records show which device version was applied to which vehicle configuration, how far the relationship between start control and existing equipment was confirmed, and which functions were tested after installation. That way, even someone else reviewing it at the next maintenance can understand the assumptions behind the judgment at the time.
Keep recording vehicle configuration changes after installation
The AF-i1 guidance states that it stores interlock usage data such as vehicle ACC, engine start, test results, and tamper-related events, and that events can be managed or downloaded with dedicated software. These records are less a self-proof of installation suitability than data for checking what happened while the device was in use. You need to keep the vehicle conditions and device information at the time of installation separately so that the context is not lost when you review the records.
When add-on equipment is fitted to the vehicle or the device is replaced, it is better not to apply past installation results automatically just because the product has the same name. A practical approach is to record in the installation documents what changed and to recheck whether the power, start-control, and mounting-environment conditions from the earlier review still hold. If you notice signs of a problem related to power or starting, the next step is not for the user to decide on the cause but to compile when it was observed and the vehicle's state and pass that on so vehicle maintenance staff and the installer can inspect it.
