One Wiper Not Working? Here’s What’s Wrong

It’s raining. You hit the wipers. One sweeps across like normal. The other just sits there doing nothing.

Most folks jump straight to “motor’s gone.”
Not the case.

If one wiper still works, the motor is fine. The issue is nearly always mechanical.

What it usually means

Both wipers are driven by the same motor.

So if only one has stopped, the fault is always after the motor.

These are the usual suspects:

• Loose or stripped wiper arm
• Worn or disconnected linkage
• Seized wiper spindle
• Bent linkage from ice or snow
• Damaged wiper transmission

Loose or stripped wiper arm

The arm sits on a splined spindle and is held by a nut.

If that nut loosens or the splines wear out, the spindle turns but the arm doesn’t.

What you’ll notice:

• One wiper dead or slipping
• Arm feels loose by hand
• Wiper may twitch but won’t sweep

Quick check:

• Lift the plastic cap at the base
• Check the retaining nut
• Look for worn splines

If the splines are gone, the arm needs replacing. Tightening won’t hold for long.

Wiper linkage failure

Very common.

Under the scuttle panel is the linkage that connects the motor to both wipers. It uses plastic joints that wear over time.

When one fails, one wiper stops while the other keeps going.

Typical signs:

• One wiper works, the other doesn’t
• Motor can be heard running
• You may hear a light knocking under the cowl

This is the most common cause, especially on older cars.

Seized spindle

The spindle passes through the body and lives in a damp spot. Over time it corrodes and starts to seize.

What happens:

• Wipers get slower over time
• One side starts sticking
• Eventually one stops

What to look for:

• Wipers were sluggish before failing
• Affected arm is stiff by hand
• System sounds strained

Left alone, this can damage the linkage or even the motor.

Ice or snow damage

Happens fast.

If the blades are frozen to the glass and the wipers are switched on, something has to give.

Usually:

• Linkage bends
• Arm slips on spindle
• Joint pops off

Big clue is timing:

• Fault started after frost or snow
• You heard a clunk when switching them on

Could it be the motor?

No.

If one wiper works, the motor is doing its job.

Check the mechanical parts first:

• Arm
• Linkage
• Spindle

How to check it yourself

You can diagnose a lot with basic checks.

• Turn wipers on and observe
• Listen for motor noise
• Check if the dead arm is loose
• Inspect the retaining nut
• Remove scuttle panel if needed
• Look for disconnected or bent linkage
• Check spindle stiffness

Be careful. These systems can move suddenly.

Is it safe to drive

Not really.

In rain, one working wiper leaves poor visibility very quickly.

You’ll end up relying on a narrow clear patch of glass.

Fine for a short move in dry conditions.
Not fine in wet weather.