It’s right after a major snowstorm, and there are ice and snow on everyone’s windshield. The best wiper blades for winter. The phone leaps off the receiver. The caller was in too much of a hurry to clean the ice off the wiper blades before turning them on. The wiper blades have become completely useless. He can hear the wiper motor running, but the blades refuse to move.Most likely, it’s the nut on the wiper arm that has worked loose from the wiper shaft. Since most wiper manufacturers have gone to this type of fastener, not many wiper transmission failures occur due to snow or ice.
The next generation of “frameless” or “aero” wipers are starting to become the norm on late-model vehicles, much to the chagrin of older drivers who only want to pay for $5 refills for older-style blades. These blades are designed to work for late-model vehicles and often a driver will notice reduced performance and wind noise if they try to go with a cheaper frame wiper. For older cars, these wipers can be a nice upgrade. Diagnosing most of the mechanical parts of the wiper system is straightforward, but diagnosing the electric or electronic components, however, is the another issue. We can break the systems down by years, and then determine how to diagnose the problem and make repairs.
There weren’t too many complicated electrical wiper systems. To go back even farther into auto history, most wiper systems were either vacuum-operated or operated by hand. There are a few exceptions, but most of those are on special models.The arrival of OBD II systems, a lot of the manufacturers tied their wiper systems into the ALDL connector. You can actually diagnose the wiper system with their scanner. Some even have codes that involve the wiper system, usually through the BCM unit or the CAN system.
You can still diagnose the entire system with the use of an ohm/voltmeter, but I much prefer the newer cars for the diagnostic capabilities using the factory scanner to operate the front and rear wiper systems.One of the other things that have changed over the years is how they work, where they’ve put all the separate components and the nomenclature that each different manufacturer uses.
Things get even more compact. It’s a variable intermittent wiper control module and it’s part of the wiper switch itself. If the test results tell you to change the wiper switch, you also get lucky with the intermittent unit being changed along with it.
Before tackling any electrical system in any car, make sure you have the latest TSBs, proper wiring diagrams, and any diagnostic information that you can get your hands on. Most good diagnostic manuals will have the impedance values and the voltage ranges in their test procedures.