Component Connection: Wiper Motors
If there is one system that vehicle owners believe is inhabited by Gremlins, it’s the windshield wipers. Unfortunately, car owners don’t normally realize there is a problem with the wiper system until they need them most – when it’s raining.
No matter what type of car you service, when it comes to wiper-related problems, the symptoms are quite similar. Some customers may complain that their vehicle’s wiper motor gets very hot before it eventually stops working. Others may tell you that the wipers go to the “straight up” position when turned off. Another common problem is the delay works intermittently. And some minivans have been known to activate the wipers when the driver uses the turn signals. (Usually, replacing the turn signal/wiper switch assembly fixes the problem.)
Some techs have heard stories that the wipers on a particular vehicle stopped working one day, but worked when the driver operated the washer fluid control. Or that the washer fluid sprays fine, but the wipers refuse to cooperate.
Most solutions to wiper malfunctions are not Gremlins, but rather could be caused by poor grounding of the wiper motor, causing the unit to draw extra amps resulting in a motor that runs hotter than normal.
Other solutions may include replacing the control module for the windshield wiper motor for the ones that act up. Or a park circuit may have gone bad, causing the wipers to stop wherever and whenever they feel like it.
If you have a customer with a wiper motor issue, one of the first things you should do is check your electronic service information to see if there was a warranty recall on that vehicle. (A few notable wiper-related recalls are mentioned later in this article.) You may be surprised at how many wiper motor malfunctions caused recall notices on various makes of vehicles.
In this article, we will look at a few wiper motor complaints on a 1997 Dodge Neon. You’ll find many of these wiper motor problems, diagnostic testing and repairs are common to all vehicle models, both import and domestic.
Warning: On vehicles equipped with airbags, refer to section 8M of the 1997 Dodge Neon Service Manual on restraint systems for steering wheel or column removal procedures.
Symptom: Wiper Motor Will Not Operate in Some or All Switch Positions
Check fuse 15 in the fuse block (see Figure 1).a. If the fuse is OK, go to Step 2.
b. If the fuse is defective, replace it and check the motor operation in all switch positions.
c. If the motor is still inoperative and the fuse does not blow, go to Step 2.
d. If the replacement fuse blows, go to Step 6.
Disconnect the motor wire connector.
Check the motor at low speed. Using two jumper wires, connect one jumper wire between the battery positive terminal 2 of the motor connector. Connect the other jumper wire to the battery negative terminal and the motor ground strap (see Figure 2). Check the motor at high speed, connect the positive jumper wire to terminal 1 of the motor connector. Connect the negative jumper wire to the motor ground strap.a. If the motor does not run (high or low speed) go to Step 4.
b. If the motor runs, go to step 5.
Using an ohmmeter, check for good ground at the motor ground strap. If it is OK, replace the motor. If it is not OK, repair the ground circuit as necessary.
Check terminal E of the wiper switch connector for continuity to ground. If it is OK, go to Step 6. If it is not OK, repair the ground circuit as necessary.
Using a voltmeter, with wiper switch connected, connect the negative lead to the motor ground strap. Connect the positive lead terminal P1 of the wiper switch connector.a. If there is no voltage, repair the wiring as necessary. If there is voltage, go to Step 2.
b. Check the wiper switch at low speed, connect the voltmeter positive lead to terminal L of the wiper switch connector. Move the wiper stalk to the LOW position. If there is no voltage, replace the switch.
c. Check the wiper switch at high speed, connect the voltmeter positive lead to terminal H of the wiper switch connector. Move the wiper stalk to the HIGH position. If there is no voltage, replace the switch.
Disconnect the motor connector and replace fuse 15 in the fuse block.a. If the fuse does not blow, replace the motor.
b. If the fuse blows, disconnect the wiper switch and replace the fuse.
c. If the fuse does not blow, replace the switch.
d. If the fuse blows, repair the wiring as necessary.
Symptom: Motor Operates Slowly at All Speeds
Remove the wiper arms and cowl screen. Disconnect the motor linkage from the motor. Connect an ammeter between the battery positive terminal and terminal 4 of the motor connector. Turn the wiper motor on and check the ampere reading.If the motor runs and the ammeter reading is more than 6 amps, go to Step 2. If the reading is less than 6 amps, go to Step 3. Note: When replacing the drive link nut, tighten to 11 to 12 Nm (98 to 106 in.-lbs.) torque.
Using an ohmmeter, check the high and low circuits for a short ground. (Refer to Group 8W, Wiring Diagrams in the 1997 Dodge Neon Service Manual.)
Check to see if the wiper linkage or pivots are binding or caught.
Source: Chrysler Corporation
Volvo Wipers & Headlamps Malfunction
Both the 200 and the 700-900 Series, under a certain condition, can have windshield wipers that seem to have a mind of their own. When that condition exists, the wipers will act up whenever the headlamps are on. They’ll come on with the headlamps even when the wiper switch is turned off. Further, if the wipers have been running and the headlamps are then turned on, you’ll find the wipers will not turn off as long as the headlamps are on.
The reason for this is that the headlamp ground [-] is disconnected or poor at the front fender, near the head lamp assembly.
The defective ground will be on the same side of the car that the windshield washer pump is on. Since the windshield washer pump also grounds there, what happens is that the circuit for the pump is getting voltage supplied to it – voltage that is intended to be going to ground [-] from the head lamps. This pump circuit goes back to the transistor circuit of the wiper delay relay and triggers the relay to turn on the wipers.
This problem only needs to happen once for you to notice how interlaced so many systems can be. It’s the ripple or trickle-down effect that can really complicate the diagnosing of some of these systems.