Scene of the Crime
One crisp Midwestern autumn morning, office complex visitors seeking open parking spots were shocked to see a driverless, package delivery box-truck moving unguided through the parking lot. Meandering left and right, the truck struck bumpers and fenders of parked cars, then hit the curb of an island containing a tree. At impact, a uniformed person rolled from under the truck into the path of the rear wheels and was fatally crushed. The truck went over a curb, hit a tree and stopped.
I learned of this horrific accident from an attorney representing an auto parts store chain. He explained that the driver had loaded his truck that morning and began his deliveries. At the office complex, the engine failed to start. Hired by the delivery service, the owner-operator was responsible for truck repairs and maintenance, so he proceeded with repairs.
Believing the starter failed, and being close to home, he had a relative go to an auto parts store to purchase a rebuilt starter motor. After installing the motor, the truck still failed to start. Deciding that either the keyswitch or neutral-start interlock switch was faulty; he dispatched his relative to buy replacement switches. His relative returned with only a keyswitch, as there was no neutral switch in stock.
Retained to determine the cause of the accident, I traveled to the shop of "Diesel Dan the Fix-it Man" to inspect the truck. There I met my client and a platoon of other attorneys and experts.
Fast-forward to the inspection: With all the experts and their attorney-clients agreeing to a protocol, we attempted to start the truck as it was received into storage. Since one of the plaintiff's allegations was that the starter motor operated by itself thus starting the engine with driver still under the truck, I needed to determine the validity of that assertion.
The keyswitch failed to spin the starter motor. Diesel Dan's mechanic found and replaced a dead battery. Now, the starter spun over, but not every time the keyswitch was operated. I requested connecting a voltmeter to the starter terminals. Voltage was present only when the starter spun over with the keyswitch in the start position.
The voltmeter was then connected to the keyswitch terminal that was wired to the "Start" terminal on the transmission neutral-start switch. The meter read battery voltage each and every time the keyswitch was moved to the start position even when the starter motor didn't run. Seeing this, there was a consensus (!) among the experts present that the starter motor functioned correctly and that the noted failures to spin over were due to an anomaly external to the starter.
At this point, I reviewed the evidence with my client. I concluded that the starter sold by the auto parts store was not faulty and intermittent starting action was due to either a faulty neutral switch or faulty wiring. Satisfied that he had a strong defense case that could lead to a dismissal from the suit, or at least a reasonable settlement, my client agreed when the manufacturer's attorney asked to remove the starter motor and other starting system components for further examination.
Still, the question nagged at me — how did the truck seemingly start by itself and run over its owner? With the starter out, on a bench and in good light, I examined it in detail.
The Smoking Gun
While photographing the starter in various attitudes, I noticed arc burns on its terminals. One burn was on the heavy stud to which the positive battery cable was connected, and the other was on the terminal post to which the wire from the neutral switch was connected. Using wiring diagrams, I confirmed these connections, if bridged, would energize the starter motor.
From witness statements and evidence from the inspection, the probable sequence of events became clear to me: The driver replaced the keyswitch, but with a faulty neutral switch, the engine still failed to start. The driver then crawled back under the truck to start the engine by bridging the starter terminals with a screwdriver. With anxiety to finish his deliveries, he failed to observe that he moved the automatic transmission lever to the "Drive" position during his service attempts. When the engine fired up with the driver underneath, the truck moved forward with fatal consequences. I learned later that the auto parts store was dismissed from this suit.