1988-1991 Mazda 929 Wiper Motor: A Guide to the 'Fully Concealed' System

Compatibility Warning: Fully vs. Semi-Concealed Wipers

Symptoms of a Failing Wiper Motor

A bad wiper motor can show several signs before it fails completely. Recognizing these symptoms can help you diagnose the problem before you're caught in a storm without working wipers.

Wipers are Slow or Erratic

If your wipers move much slower than they used to, especially on the highest speed setting, it's a strong sign the motor is wearing out. Internal components can get clogged with grime or simply wear down, increasing resistance and slowing the motor's operation. You might also notice jerky or hesitant movement across the glass.

Wipers Only Work on One Speed

Your wiper switch allows for multiple speeds, but a failing motor might lose this function. If the wipers only move at a single speed regardless of the setting you choose, the internal circuitry of the motor is likely compromised.

Wipers Won't Park Correctly

A key function of the wiper motor is the 'park' feature, which returns the blades to their resting position at the bottom of the windshield when you turn them off. If your wipers stop in the middle of the glass or wherever they happen to be when you hit the switch, the park circuit inside the motor has failed.

Humming Noise Without Movement

If you turn on the wipers and hear a distinct humming or buzzing sound from the base of the windshield but the arms don't move, the motor is receiving power but is unable to operate. This could be due to a seized internal gear or an issue with the connected wiper linkage.

Wipers Don't Work at All

The most obvious symptom is a complete failure to operate. When you turn the switch, nothing happens—no sound and no movement. While this can point to a dead motor, it's important to check other potential causes first, like a blown fuse or a faulty switch, before condemning the motor.

Diagnosing the Problem

1. Check the Fuse: The first and easiest step is to check the fuse for the wiper circuit. A blown fuse is a common cause of wiper failure. If a new fuse blows immediately, it indicates a short circuit in the motor or wiring that needs further investigation.
2. Listen to the Motor: Turn the ignition on and activate the wipers. Listen carefully for any humming sounds coming from the cowl area (the panel between the hood and windshield). A hum means the motor is getting power, suggesting the problem is mechanical (a seized motor or linkage). No sound suggests an electrical issue.
3. Inspect the Wiper Linkage: Sometimes, the bushings in the wiper linkage (or transmission) can break or pop off. This will disconnect the motor from the wiper arms, resulting in the motor running but the arms not moving. A visual inspection under the cowl may reveal a disconnected linkage.
4. Test for Power: For those comfortable with a multimeter, you can test for power at the motor's electrical connector. This involves removing the cowl panel for access. If voltage is present when the switch is on, but the motor doesn't run, the motor itself has failed.

Buying a Used 1988-1991 Mazda 929 Wiper Motor

Given the age of these vehicles, a used OEM wiper motor is often the most practical and affordable option. New OEM parts are likely discontinued, and aftermarket quality can be inconsistent. Here’s what to look for when buying a recycled part.

Why Choose Used OEM?

An original equipment (OEM) motor was designed by Mazda specifically for the 929. It offers the best guarantee of proper fitment and function, especially concerning the complex 'fully concealed' system. A good used OEM part from a low-mileage vehicle is often more reliable than a brand-new, cheaply made aftermarket alternative.

Inspection Checklist

• Verify Part Numbers: If possible, match the part number from your old motor to the used one. Look for HE0167340, HE0167340A, or HF05-67-340A.
• Check the Connector: Inspect the electrical connector pins for any signs of corrosion, melting, or damage. Clean pins are crucial for a good connection.
• Examine the Housing: Look for excessive rust or physical damage to the motor's case. While some surface rust is normal for a part of this age, deep corrosion can indicate water intrusion.
• Ask About the Donor Vehicle: Inquire about the mileage of the car the motor came from. A motor from a lower-mileage vehicle is always preferable.

Replacement Overview

Replacing the wiper motor is a moderately difficult job that a DIY mechanic with basic tools can typically accomplish in 1-2 hours.

Difficulty: 3 out of 5

The general steps are as follows:

1. Disconnect the Battery: Always disconnect the negative battery terminal before starting any electrical work.
2. Mark and Remove Wiper Arms: Use a piece of tape to mark the 'parked' position of the wipers on the windshield. Then, lift the small cap at the base of each arm and remove the retaining nut. The arms may be tight; gently rocking them or using a wiper arm puller tool will help free them.
3. Remove the Cowl Panel: The plastic panel at the base of the windshield must be removed to access the motor. It is typically held on by several clips and screws.
4. Disconnect and Unbolt the Motor: Disconnect the motor's electrical harness. Unbolt the wiper linkage assembly (the motor and transmission are usually removed as one unit).
5. Separate Motor from Linkage: On a workbench, unbolt the old motor from the linkage assembly. Before installing the new motor, it's a good idea to connect it to the harness and cycle it once, allowing it to return to its park position.
6. Installation: Bolt the new motor to the linkage, reinstall the assembly into the car, and follow the removal steps in reverse.

Known Issues, Recalls, and TSBs

For a vehicle of this age, specific TSBs for the wiper motor are not readily available. However, there was a significant recall concerning the ignition switch that could affect all electrical components.

• Recall NHTSA 15V674000 (Mazda Recall 8715J): This recall was for an ignition switch that could overheat due to carbonized grease, potentially causing a fire or loss of electrical power to various systems, including the wipers. While this recall was issued for 1993-1995 models, the underlying issue with aging electrical components is relevant. A faulty ignition switch could mimic a failed wiper motor by cutting power to it.
• No other recalls directly pertaining to the wiper motor or wiper system for the 1988-1991 Mazda 929 were found in the NHTSA database.

Cost Comparison

Frequently Asked Questions