Hi Tech Windshield Wiper System Problems
We have come a long way from the manually operated basic windshield wipers of the early 30s to the high tech rain sensing delay systems of today. This article will walk us through some of the fancy systems that have intermittent and water sensing capabilities. Learn how they operate and discover some of the common problems associated with them.
Delay Wiper Systems
It’s pretty common today to find an intermittent or delayed wiper system on an automobile. Most of these systems operate using a timer module that pause the wiper sweep for a controlled amount of time. It is also common when the blades pause they will not actually park, but stay slightly elevated from the bottom of the glass. This not only gives the driver and unobstructed view, but they can tell the difference between the wipers being turned off or in a pause mode.
Manufacturers will handle intermittent wipers differently, but many carmakers use a module that is mounted in the cover of the wiper motor. When erratic operation is experienced by drivers diagnosis usually heads in two directions. Malfunctions in the rotating switch that adjusts the delay time are just as likely as problems with the module that carry out these orders. Often it’s the dealership level technicians notified through service bulletins that become most familiar with the individual components likely to fail.
Speed Sensitive Wipers
This is an interesting option that is used to help improve visibility under different driving conditions. As you might expect, the faster you travel in a rainstorm, the more water will hit the windshield. Some advanced wiper systems are able to monitor how fast the automobile is traveling through the vehicle speed sensor. Manufacturers can also use the body control module to interpret input data and then ultimately control the output speed the wipers swipe the windshield.
Rain Sensing Wipers
Another advancement would be an automobile that is capable of sensing not only when it starts to rain and automatically turn on the wipers, but to determine how hard it’s coming down and adjust the speed accordingly. The main part of these systems is a detection sensor located in the top of the windshield behind the rear view mirror or mounted in the dash pad.
The sensors are optical sensing components that are able to determine the weather conditions by the light that is reflected back to the sensor. Reflected light changes as moisture begins to accumulate on the glass allowing less to reach the sensor. Most manufacturers have enabled controls so the driver can override the system and adjust its sensitivity. Erratic operation or phantom wipe can be caused by driver mounted accessories that reflect light or problems with the detection sensor.
Phantom Wipe Problems
Phantom wipe is a nickname for an intermittent and unwanted wiper operation. This can be multiple sweeps or a single one for no apparent reason. Drivers might explain these as occurring when going over bumps or when turning the steering wheel. Intermittent problems are some of the hardest to diagnose. Sometimes the phantom condition can happen so seldom the only way to approach the problem is to start guessing and replacing selected components known to have a high failure rate.
On older GM vehicles that experience unwanted wiper operation when turning the steering wheel or going over bumps, the cause is often a malfunction of the wiper switch. This is a column mounted combination switch that also controls the turn signals. This should not be confused with the combination lever that actually operates the electrical part inside the column. On more modern vehicles diagnosis can be even more complicated as a faulty rain sensor also has the capability of activating a wiper sweep.
Automotive consumers should be aware that fancy high-tech windshield wiper systems were developed as a selling feature to increase sales. When operating correctly, they can be extremely convenient and useful. When they malfunction and start phantom wiping on a dry sunny day, they turn from being a luxury to an annoyance. The more complicated the system is the harder it is to diagnose problems. Vehicles with speed sensitive and rain sensing functions are often controlled by a body control module that can only be efficiently diagnosed and repaired at a dealership.