F-150 Windshield Wipers Won’t Turn Off? | Quick Fix Guide

Nothing steals a calm drive faster than wipers swiping on a dry glass. If your Ford F-150 wipers keep running with the switch at OFF, use this hands-on guide to diagnose fast and stop the chatter safely. You’ll find quick checks, a clear test flow, and repair paths that match common model years.

Fast Diagnosis: What To Check First

Before diving deep, take two minutes to rule out simple triggers and protect the glass.

• Set the wiper knob fully to OFF, not INT. Some stalks have a tight detent.
• Turn off rain-sensing mode if equipped, then power cycle the truck.
• Lift the blades off the windshield to prevent chatter while you test.
• Pull the wiper motor relay to stop motion during wiring checks.

Common Root Causes At A Glance

The table below maps the most likely faults to the symptom “wipers run with switch OFF.”

Likely Cause	Typical Clue	Usual Fix
Multifunction stalk switch	Wipers stuck on one speed or random INT	Replace the stalk switch
Stuck relay / Smart Junction Box logic	Relay clicks, wipers run until relay pulled	Swap relay or repair SJB/GEM
Wiper motor park switch	Wipers return to park then restart	Replace the motor assembly
Rain sensor misread	Runs only in AUTO, glass clean	Clean sensor area, turn AUTO off
Wiring short to power	Related to recent accessory work	Find rub-through, repair harness

Why F-150 Wipers Keep Running

On most model years the stalk sends low-current signals to a control unit—GEM on older trucks, later the Smart Junction Box or Body Control Module. That unit drives the motor and monitors a “park” signal inside the motor gear. If the stalk contacts stick, a relay welds, or the park switch loops power, the blades keep moving even with the knob at OFF.

Close Variant: F-150 Wipers Won’t Shut Off — Causes And Fixes

This section walks through faults by part so you can match clues to the right repair with confidence.

1) Multifunction Stalk Switch

Wear inside the stalk can bridge the INT or LOW contacts, feeding a false run call. Tell-tales include wipers locked on the lowest delay, washer works, and tapping the stalk changes nothing. The fix is replacement; it’s usually two screws and one connector behind the wheel shroud. Clear the battery negative before unplugging airbag-adjacent panels.

2) Relay Or Smart Junction Box

Many F-150 generations route power through a serviceable wiper relay. If contacts weld closed, the motor gets power regardless of the stalk. Pull the relay as a safe stop, then swap with a known good unit. If your year uses a Smart Junction Box with solid-state drivers, faults inside the module can mimic a stuck relay. Some shops repair these boards; others replace the unit and program it.

3) Wiper Motor Park Circuit

Inside the motor is a cam and switch that feeds power until the blades reach the parked spot. When that switch shorts, the circuit can loop and restart the cycle forever. Signs include blades that park, pause, then sweep again, or wipers that only stop when the relay is pulled. Replacing the motor assembly cures a failed park switch.

4) Rain-Sensing Autowipers

Trucks with AUTO wiping rely on a sensor near the mirror. Smudges, a misplaced gel pad, or a stunned sensor after a windshield swap can trigger wipes on a dry day. Turn off AUTO in the menu, clean the glass over the sensor, and test again. If the wipers stop misbehaving only with AUTO off, you’ve found the match. For setup guidance, see the official rain-sensing wipers how-to for menu steps and sensor notes.

5) Wiring Fault Or Water In Connectors

A rubbed harness or water inside a connector can feed constant power or cross-talk the control pins. This shows up after bumper lighting work or cowl leaks. Look for fresh splices, crushed loom, or green corrosion in the wiper motor plug.

Model Year Guide: What Your Truck Uses

Ford updated the control strategy across generations. Use this quick map to match parts language you’ll see in guides and parts stores.

• 1997–2003: GEM controls the wipers; serviceable relay; common water leaks behind the dash.
• 2004–2008: Smart Junction Box era; relays integrated; stalk faults still common.
• 2009–2014: SJB/BCM with separate relays in many trims; rain-sensing option on upper trims.
• 2015–2020: BCM logic with rain sensor option; many “stuck on low delay” cases traced to stalks or motors.
• 2021–present: BCM plus menu-driven AUTO settings; software resets sometimes clear odd behavior.

Step-By-Step: Stop, Test, And Fix

Step 1 — Stop The Motion Safely

Lift the blades. Pull the wiper relay or the correct fuse to halt the motor. If your model has solid-state control, disconnect the battery after opening the driver window to avoid lockouts.

Step 2 — Rule Out Autowipers

Open the settings menu and switch off AUTO wiping. Wipe the area ahead of the mirror, then test in OFF. If the wipers calm down now, leave AUTO off until you service the sensor or re-seat its gel pad.

Step 3 — Quick Relay Swap

Locate the wiper relay in the fuse panel, usually under-hood. Swap it with another identical relay in the box. If the wipers stop, install a new relay and you’re done.

Step 4 — Stalk Switch Check

With the relay back in, turn the knob from OFF through each detent while watching the cluster wipe icon. If the icon flickers or the wipe rate ignores the knob, suspect the stalk. Removing the upper and lower column shrouds exposes two screws and the harness plug. Install the new unit and retest.

Step 5 — Park Circuit Test

Set the stalk to OFF with the relay installed. If the wipers return to the bottom then immediately sweep again, the park switch is likely shorted. You can confirm by unplugging the motor: if the blades stop only when you pull the relay or unplug the motor, replace the motor.

Step 6 — Harness And Water Checks

Trace the loom from the column to the junction box and out to the motor. Look for pinched runs near the hood hinge and cowl. Dry any damp connectors with contact cleaner, then pack with dielectric grease.

Fuse And Relay Pointers

Ford moved fuse and relay layouts over the years, so use the owner’s manual for the exact cavity number. Keep a spare relay in the glovebox, and note the puller tool location in the fuse panel, if fitted. Carry a spare mini fuse. Label relays with tape for tracking.

For diagrams, the online owner guide has cavity charts by year. Open the official Ford owner’s manual hub, select your model year, then see the fuse specification chart inside the manual.

Cost And Time: What To Expect

Fix	Parts Cost (USD)	DIY Time
Relay replacement	10–25	10 minutes
Stalk switch	60–140	30–60 minutes
Wiper motor	120–260	60–90 minutes
SJB/BCM repair	150–400 service	Shop dependent
Rain sensor pad	10–30	20 minutes

Pro Tips To Prevent Repeat Problems

• Use washer fluid, not dry wipes. Dry friction speeds motor and linkage wear.
• Replace old blades. Draggy blades stress the park switch and arm pivots.
• Keep the cowl drains clear so water stays out of connectors and modules.
• After windshield work, verify the rain sensor pad sits flat with no air gap.

Real-World Clues And Fix Paths

Locked on low delay with normal washers points to the stalk. Stops only when the relay is pulled points to a stuck relay or a motor that back-feeds the park circuit. Runs only in AUTO points to the rain sensor. Random wipes after car-wash day point to water in a connector or a cowl leak. A truck that ignores the stalk and still wipes with the relay removed points to a harness short to power.

If you’re chasing a module fault, note any other odd lights or chimes. A Smart Junction Box with water damage may also throw turn signal, horn, or interior lamp gremlins. Dry the box, clean the pins, and reseal the cowl. Shops that specialize in board repair can often revive these units with fresh drivers and solder work.

Tool List For A Clean Repair

You can solve most cases in a driveway with basic hand tools. A trim tool set helps you open the column shrouds without marks. A small Torx driver fits the stalk screws on many years. Add a relay puller or needle-nose pliers, a multimeter for quick voltage checks, contact cleaner for wet plugs, and dielectric grease for reassembly. Painter’s tape protects the glass edge while you lift the arms. If you swap the motor, mark blade park position on the glass with tape before removal so alignment stays easy during install.

When To Call A Shop

If your scan tool shows wiper faults, or the wipers run even with the relay removed, you likely have a harness short or a module driver fault. A dealer or auto-electric shop can run pinpoint tests, check software, and program a replacement module if needed.

Bottom Line And Safe Settings

Most F-150 cases trace to a worn stalk, a sticky relay, or a failed park switch. Start with AUTO off and a relay swap, then move to the stalk and motor. Use the manual for fuse maps, and save your glass by lifting the blades during tests. With a clear test flow you can stop the wipe, fix the cause, and get back to a quiet cab.