An ignition interlock installation is a short appointment that has very long-term consequences for a driver. To advise a driver or manage a fleet safety program or service center, you should know all of the details of an installation very well. In most cases, the problems of compliance with the terms of an interlock installation revolve around one or more details that were not completed correctly on the day of the installation.
Before the vehicle goes on the lift
The appointment starts with paperwork. The installer wants to see the papers authorizing the monitoring, the required device, the frequency of the reports, and possibly special features like a camera, GPS tracking, or even different intervals for re-testing (vs. The state’s standard for example). He or she needs to verify that the installed device will in fact report correctly and thus satisfy the terms of the order.
Vehicle types, such as push-button start systems, hybrid and electric vehicles and even aftermarket remote starters, as well as certain European vehicle types with unique electrical architectures, require specific wiring approaches or even manufacturer-approved wiring harnesses.
What stops an installation before it starts
- A weak or failing battery, which produces false power events once the device begins drawing current
- Existing aftermarket alarms or starter kill circuits that conflict with interlock relay logic
- Company vehicles without written owner consent for wiring modification
- Ownership documentation that does not match the person named in the order
Wiring, calibration, and the handset
The connectors for constant power, switched ignition, ground and the starter circuit are connected at the designated positions. The control unit is mounted out of sight. The handheld unit is connected to the dash in a position which allows the driver to use it while seated properly with the seat in the proper position. The routing of the cables for the handheld unit is important. A cord routed across a knee bolster will stretch and likely suffer damage within weeks.
The alcohol ignition interlock device comes pre-calibrated, with a certificate supplied by the manufacturer, or, the interlock can be calibrated by your service center using their own bench test equipment. The critical date here is the calibration date and NOT the date of installation. This is the date when the first service appointment must take place. For the initial programming the following settings are entered, the lockout parameters for breath test failures, the fail point for the breath test, the retest period after a passing test and the service interval.
Verification before handover
Depending on the jurisdiction, the installed ignition interlock will require a functional test by the installer. This test will typically confirm that a proper sample of air will enable a start of the vehicle’s engine, that the starter circuit for the vehicle will be disabled for non-acceptable air samples, that a rolling retest will prompt the driver for additional tests at the scheduled time for additional samples, and that the interlock’s event log is updated and reported to the required portal. Most jurisdictions require the installer to take and attach photos of the installed ignition interlock, as well as the odometer reading and the Vehicle Identification Number (VIN) of the vehicle on which it was installed.
Driver training that prevents violations
The education required to prevent repeat offenses consists of more than handing a driver a pamphlet on how to provide a proper breath sample. Most Ignition Interlock Devices require a steady blow into the mouthpiece and typically will recognize a ‘hum’ or ‘inhale’ and will log the sample as complete. Incomplete samples will typically log as a refusal in monitoring authorities’ databases.
It is important to also advise the driver of mouth alcohol sources such as mouthwash, breath spray, some cold medications and fresh bread to name a few. Also be sure to advise the driver of the proper way to collect a sample for a rolling retest, temporary lockouts versus permanent lockouts and who to contact prior to a lockout occurring.
The five points every driver should be able to repeat back
- How to deliver a valid sample on the first attempt
- What to do after a failed reading rather than trying again immediately
- The date of the next required service visit and the grace period attached to it
- That another person blowing into the handset is a circumvention event, not a workaround
- Which faults require a tow and which can wait for a scheduled appointment
Service intervals and what each visit produces
Typically installations are monitored and serviced on a cycle of calibration, download and reporting. Service centers are typically allowed a set amount of time to download the information from the installation and report on the results.
Drivers in Northern Virginia are usually better served by booking car breathalyzer installation in Manassas at a shop that also handles the recurring calibrations, since keeping one service history in one place makes every later report easier to defend.
| Visit type | Typical timing | Main outputs |
| Installation | Day one | Certificate of installation, driver training record, first data baseline |
| Routine service | Every 30 to 60 days | Calibration, log download, compliance report to the monitoring authority |
| Unscheduled service | As needed | Fault diagnosis, handset or module replacement, lockout reset |
| Removal | End of the monitoring period | Final data report, circuit restoration, removal certificate |
Reading the log the way a monitoring authority does
Upon downloading the information and running a report, it is best for service center personnel to review each report prior to releasing the customer. They can then flag any problem areas and explain in simple terms. This approach is far better than having some reviewer try to deduce problems from the same raw codes months later.
Removal and the record that outlives it
Remove the ignition interlock device and starter cable from your vehicle. Have both the service center where the device was installed and yourself keep a copy of the removal certificate and final summary of compliance for potential future use by the state to verify reinstatement.
