Magazine Today
Thro ugh the monsoonlkra in, you see some sort of flashing lights ahead of you. But despite the best efforts of your windshield wipers, all you can see are blurry blobs of yellow, amber, and red. Slowing to half speed, you continue to press for RWA rd through the deluge.
Suddenly you realize that those flashing blobs are the warning lights of a stopped school bus, and children are running across the road in front of you. Fortunately, your brakes work infinitely better than your windshield wipers. Once it’s dry and sunny age in, grab a tape measure and head for the garage.
Lift one of the wiper arms (it’s usually easier to grab the driver’s-side arm) off the windshield against its spring tension and keep lifting until the pivot point locks the arm upright.
Look for contaminated rubber inserts, which can be caused by road film or carwash chemical adhesion. Inspect the wiping edges for “park set rubble;” the term used to describe hardened finely-cracked inserts that have been exposed to the sun for too long in an In 10 minutes, you can replace your streaky view of the world through a windshield with fresh wiper blades.
HOW IT WORKS
the rubber insert of a wiper blade sweeps across your wet windshield, a wedge of water builds up in front of the rubber-a squeegee effect-and the wiper displaces that water elsewhere_ What’s left is clean, clear glass that allows you to continue on your way safely_ That’s the way it’s supposed to work. The illustrations to the right show some of the reasons why it may not.
Other reasons may involve components that work behind the scenes-actually, behind the cowl or dashboard of your car. They include the splined shafts that the wiper arms pivot on, the mechanism that creates the back-and-forth pivoting motion, and the electric wiper motor that drives the whole system. A small nut under a cosmetic plastic cover jams the wiper arm onto the splines of its shaft.
The splines keep the shaft from slipping in the arm as it turns in one direction and then the other, over and over and over. This reciprocating motion is created by a metal crank-type linkage assembly that’s attached to each wiper arm’s splined shaft, and to the wiper motor with another splined shaft.
Picture the chugging action of a steam locomotive’s piston and drivewheels and you’ll get the idea. Rear wipers-found on minivans, SUVs and some sport coupes-work the same way, except the reciprocating mechanism, is much smaller and built into the motor.
Last word
Wiper speed depends on the amount of voltage that’s sent to the motor from the wiper switch-low voltage equals low speed, high voltage equals high speed. Intermittent wiper action is created by a separate electronic module wired between the switch on your dashboard or steering column stalk and the motor. Some cars even have electronically controlled road speed-sensitive wipers that wipe faster the quicker you go.
