While many of the broken and defective things we work on in the repair shop are unpredictable and not related to customer use or abuse, pretty much most windshield wiper system failures are avoidable.

Although almost everything else on today’s vehicles has evolved from the dinosaur era, windshield wipers still contain a lot of prehistoric DNA.

A simple electric motor is mechanically linked to a series of links and rods, which are connected to the wiper arms.

Turn the switch and voila, you have action – unless, of course, you forgot to check to see if the wiper blades were frozen to the windshield, or if the linkage was encased in ice from last night’s sleet storm.

Almost all wiper systems have some type of fail-safe. Certain vehicles will use a relay to shut the power off to the motor if it can’t complete a wiper blade cycle sweep due to frozen blades. Others use a wiper arm mounted to the linkage with a nut that will loosen off under the same conditions (letting the linkage move without the arm).

But even with these helpful features, auto shops are busy every winter with wiper system repairs; these can often run into the hundreds of dollars to replace motors and linkage assemblies, and it’s very easy and free to avoid this wallet pain.

First, every time you park your vehicle, make sure the wipers are turned off. Sounds simple, right? But this is the number one cause of wiper system failures. Get into the habit no matter what the season – and give up the practice of leaving the wiper arms raised off the windshield to prevent the blades from freezing to the glass. In windy conditions, a wiper arm can snap down hard enough on the windshield to crack it, especially if the blade can swing on the end of the arm exposing the metal hook to the glass. A better idea is to sheath the wiper blades with a plastic bag and leave them in their normal position.

The second most common cause of wiper failures is letting snow and ice pack up at the bottom of the windshield. This can prevent the wipers from completing a cycle and will damage the linkages. When clearing the windshield before heading out, use the brush and your fingers (if needed) to dig out all that snow under the arms.

If you fire up your faithful chariot and only one wiper moves, you probably have the type that has a release-style nut attaching the arm to the linkage pivot. To check, with the wipers turned off, see if you can move the dead wiper arm by hand. If it moves, return it to the parked position and pop off the plastic cap/cover at the bottom of the arm (where it attaches to the pivot). Tighten the nut and you’re away to the races!

If your daily ride has been parked outside during a particularly nasty freezing rain storm and you suspect ice has formed around the linkage under that plastic cowl panel at the bottom of the windshield, you can thaw it out with cool (not hot or warm) water.

If you are faced with replacing a wiper linkage and have recovered from the shock of the estimate (these units range from $200 to $750 on most mainstream vehicles), you may be able to source the plastic or nylon insert that causes 99 per cent of the failures of these units. Parts companies like Dorman make wiper linkage repair kits; for a few dollars you can buy just an insert that holds the linkage arms together rather than a complete unit (also called a wiper transmission).

Finally, a word on those poor little windshield washer jets that get beaten into pieces by snow-brushes every winter – as your vehicle ages, the resins in these plastic nozzles dry out, making them brittle. Avoid harsh treatment with a snow-brush to clear ice or snow away from these hood-mounted units and use your hands instead.