Is It Time To Replace Your Windshield Wiper Motor?

Many of us have been in this scenario: driving down the road in the rain, you turn on your windshield wipers only to have them do an inadequate job clearing your field of view. Perhaps the wiper is flopping around, has left the windshield totally, or maybe the wipers are no longer wiping in sync and crashing into one another. Maybe the wipers don’t operate at all.

Wipers that don't work properly is a safety issue and one that can cause you a lot of stress. You can certainly take your vehicle to a mechanic and pay them to deal with it, but that can cost a lot of money. The good news is that replacing your own windshield wiper motor or transmission is easier than you think and can be done with a few simple tools and a little time.

Symptoms related to wipers that don’t operate correctly

Some definite signs point to a windshield wiper motor or transmission failing:

• Your wipers could be moving slower than normal
• Your wipers stop (“park”) in the wrong position when turned off
• The wipers simply do not move
• You hear odd or loud noises from the cowl area when the wipers are on
• A burning smell or smoke is observed when the wipers are turned on

If you have any of these issues, there is a good chance you will need to replace your wiper motor or transmission. Diagnosing the issue correctly is very important, though.

“Repairing inoperable wipers all starts with the correct diagnosis,” said Lemmy, an ASE-certified mechanic, author, and video host for Dorman Products. “If the wiper won’t operate at all speeds, the problem may lie within a pulse board. If the wipers refuse to operate at all, you’d do well to test for power at the appropriate pins at the wiper motor harness and the switch. And for mechanical issues such as improper parking or overshooting the windshield, the transmission should be examined for proper operation.”

Once you’ve narrowed down the culprit, setting out to replace the faulty part is the next step.

The Cure for Headaches

In many instances, complicated diagnosis isn’t an expedient solution. In other cases, the long-lived wiper system sometimes has several parts that have reached the end of their useful lives. To avoid repeat labor and sidestep narrowing down the task of assessing the health of many components, you might be further ahead to replace the entire motor and transmission at the same time.

“If the wiper motor itself needs replacement, the job isn’t particularly difficult, though in many cases the wiper motor and transmission both need to be removed from the vehicle’s cowl,” according to Lemmy from Dorman Products. “To prevent doing the job twice, many DIYers find it prudent to replace both the motor and transmission as a complete assembly.”

The added initial cost of replacing the entire assembly in one repair is not as significant as you might think, and you have the added peace of mind of knowing that unlike many motors offered by remanufacturers, complete Dorman assemblies use only new components.

Replacing the Motor Assembly

Replacing the assembly is a fairly simple process. Start by removing the negative battery cable from the battery terminal. With almost all work relating to the windshield, cleanliness counts. Now’s a great time to wipe away any leaves or mud that have accumulated in the cowl area, and that is especially true as you remove components, so clean as you go. From there, follow these steps:

• Remove the decorative plastic caps at the base of your wiper arms to expose the fasteners
• Loosen with a suitable tool and remove the arms
• Remove the vehicle’s cowl. Raising or lowering the hood multiple times throughout this process may be necessary to gain sufficient access
• Disconnect the wiper motor harness
• Remove and fasteners holding the transmission and motor to the vehicle
• Install the new assembly using the correct fasteners and reconnect the harness providing power to the wiper motor
• Reinstall the wiper arms
• Reconnect the negative battery cable

The process is a straight bolt-in replacement. There are a few things to be cautious of, according to Lemmy from Dorman Products.

“When working on the wiper system, there aren’t too many ‘gotcha’ moments, but one part that can get a little tedious is indexing the wiper arms correctly. The arms, normally splined, can often take a little time to get lined up and wiping the windshield correctly. Making some indexing marks can sometimes be helpful, but I’ve spent some time adjusting them when I got sloppy with my marks,” he laughed.

A tip we’d offer is to take photos before disassembly to see exactly how things went together—it will help you reinstall the new parts in the correct order and location. By taking a few precautions and adding extra time to plan your work, you can replace the windshield wiper motor assembly in your car, truck, or SUV in short order, saving you time and money.