Q My questions involve the story where a 4-foot chunk of snow or ice flew off the top of a trailer, hit the driver's windshield and activated his air bags. His car was then sent into an electrical pole on the opposite side of the road. The driver later died.
I thought the front air bags deployed only when there was an impact around the front bumper. Did the air bags malfunction? Or are air bags designed to go off when the windshield is hit? If so, should the air bags go off when the windshield is hit? The sad irony, however, is that the driver, when hitting that pole, no longer had air bags to protect him.
A Automotive air bags are triggered when the vehicle experiences a certain level of forward deceleration, not by impact damage to the vehicle. The air bag sensors contain accelerometers that monitor the vehicle's dynamics and trigger the air bags when the vehicle experiences a deceleration force of roughly 7 Gs, equivalent to a sudden stop against an immovable object at roughly 12 to 15 miles per hour.
Many of today's air bags offer multiple levels of deployment based on level of deceleration, and are supported by seat-belt pre-tensioners that automatically tighten the belts at the initial moment of impact, thus helping keep the occupant properly positioned in the seat to allow the air bag to fully deploy before the occupant's forward movement enters the zone of deployment.
Air bags are technically described as "supplemental restraint systems," meaning they are engineered to deploy only in an "event" serious enough to potentially cause serious or fatal injuries to the occupant.
In the tragic story you described -- and in a fatal crash I investigated several years ago -- the vehicle hit or was hit by something hard enough to trigger the air bags, then continued forward to a second severe impact. Since air bags are engineered to fully deploy and begin deflating in just over one-tenth of a second, the expended air bags could not protect the occupant from fatal injuries.
Q We have had our Taurus since 1999. In the last three to four years we've had an increasing problem in winter with the windows fogging over and turning to ice. While driving I have to put down the windows to see out. Last year I had the heater core replaced. This fall we found a leak by the windshield where water was coming in and the carpet insulation was really wet in a few places. So we took the carpet out. But we are still having the problem.
A Does the air conditioning system in your vehicle still work properly? In the "defrost" mode, the compressor will engage and the A/C will function as a dehumidifier to remove moisture from the cabin air. If the A/C doesn't work, "defrost" won't work well.
You could try directing airflow from the HVAC system to the dash vents and aim the side vents at the side windows. And there's nothing wrong with using a windshield scraper on the inside of the glass to help remove the frost.
Since the fogging is a result of moisture inside the vehicle, the windshield leak may have soaked more than just the front carpet. Anything you can do to dry out the interior, including removing/drying carpets and padding, will help.
And finally, thoroughly clean the inside surface of all glass. Use an automotive glass cleaner and wadded up newspaper. The cleaner the glass, the less prone it is to fogging.