The rear wiper and tailgate electrics

The tailgate is a door opened daily, and through its hinge runs a harness feeding several systems at once. So the symptoms here are almost always grouped.

What runs through that loom

• The rear wiper and its washer.
• The heated rear window — covered in its own article.
• The lock and release actuator.
• The reversing camera.
• Lights on the tailgate.
• The screen antenna on some cars.
• The power tailgate, where fitted.

The main clue: if two or more of that list have failed, look at the loom rather than each component.

Wiring in the loom

The harness flexes every time the tailgate opens. After a few years the conductors fatigue inside the insulation — from outside the wire looks intact.

The sign: everything works intermittently, or depending on tailgate position.

The repair: restoring the conductors in the loom. Standard work, but it needs access.

Another cause: moisture entering the loom and corroding the conductors from within.

The rear wiper specifically

The motor hums, the blade stays put — worn splines on the shaft. The most common mechanical failure, repaired by tightening or replacing the nut and splined joint; the same mechanics as the front — covered in the wipers article.

Nothing at all — fuse, motor, or wiring.

It will not park — the park position sensor in the motor.

It runs only in reverse gear — that is not a fault: on many cars the rear wiper operates automatically in reverse if the front wipers are on.

The rear washer

No spray with the pump running — a hose has come off or chafed through. It runs from the reservoir the length of the car, so there are many places to fail.

In winter — frozen fluid in the hose; it thaws slower than the front, because the hose is longer and colder.

A blocked jet — clear it gently with a needle.

Camera and lighting

Bars in the image — almost always the cable in the loom.

A black screen — camera supply or the reverse signal.

A misted camera — a failed housing seal.

The camera is covered in the parking sensors and camera article.

What diagnostics shows

Body module codes — per circuit: wiper, heater, lock, lighting.

Tailgate switch status — if it lies, the car will not lock and will not sleep; covered in the central locking article and the parasitic drain article.

Camera codes — open circuit or no signal.

In short

• Two or more tailgate failures mean the loom, not individual components.
• Motor humming with no blade movement means worn shaft splines.
• A rear wiper that runs in reverse gear is a feature, not a fault.
• Bars in the camera image mean the cable in the loom.
• A lying tailgate switch stops the car sleeping.

Download the app — body electronics codes are read with an ELM327 adapter over Bluetooth SPP on Android.