Wipers that quit in a downpour leave you driving blind at speed, in a coach that needs far more room to stop than a car. Trouble usually shows up in one of these ways:
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The wipers don't move when you switch them on.
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They move slowly or labor on wet glass.
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They stop mid-windshield or won't return to park.
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One speed works and the other doesn't.
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The motor hums or clicks, but the arms stay put.
Sometimes a new RV wiper motor is the right fix. Before you order one, spend half an hour finding out which part failed, since a blown fuse, a corroded ground, or a worn linkage can look exactly like a dead motor.
Diagnosing The Problem
Work through these checks, the first two are super simple, and the third just needs a basic multimeter.
1. Start at the fuse panel
Your chassis manual will show which fuse or breaker protects the wipers. If the breaker has tripped, reset it. If it trips again, ice-packed blades or a binding linkage are the usual causes. Never swap in a higher-rated fuse, since that only moves the damage somewhere else.
2. The ground and connector
The motor's wiring sits right in the path of road spray. Look for green or white crust anywhere on the wires, bent pins, or a plug that wiggles loose, and make sure the ground strap to the chassis is clean and tight. Clean any corrosion with contact cleaner, reseat the plug, and add a little dielectric grease.
3. Is power reaching the plug?
With the ignition on and the wipers on low, connect the multimeter's black lead to a clean ground and the red lead to the low-speed pin, then repeat for high. You should see close to 12 volts on each, and your coach's wiring diagram will show which pin is which. If no power reaches the plug, check the fuse and wiper switch first, then look further upstream at a relay, the wiring, a control module, or a worn RV battery switch causing voltage drop.
4. Watch the motor shaft
Have a helper run the wipers while you watch the motor's output shaft. If it turns but the arms don't, look for a loose crank arm, a worn linkage or pivot shaft, or a slipped arm. If power reaches the plug and the shaft stays still, the motor has failed. If it hums without turning, disconnect the linkage, and if the motor then spins freely, the linkage is binding.
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What you find |
Most likely cause |
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Breaker keeps tripping |
Binding linkage, frozen blades, or a short |
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No power at the plug |
Switch, relay, wiring, or control module |
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Power at the plug, shaft doesn't turn |
Failed motor |
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Shaft turns, arms don't |
Loose crank arm, linkage, pivot shaft, or slipped arm |
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Only one speed works |
Worn motor, or no power on that speed's wire |
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Wipers stop mid-windshield when switched off |
Park switch inside the motor, or its power feed |
How to Replace an RV Wiper Motor
Most owners can replace an RV windshield wiper motor in an afternoon. Most of that time goes into reaching the motor, usually behind the front cap or under the dash. Beyond basic hand tools, you'll want a wiper arm puller and painter's tape.
Which motor fits your coach
Motors that look alike can differ in torque (the ones we carry run from 32 to 85 Nm), park type (dynamic park or coast-to-park), and pin layout. Too little torque will struggle to push large Class A arms, and the wrong park type won't stop your RV wiper arms and blades where your coach expects. Read the label on your old motor before you order, and if it's worn off, call us with your coach's year and model.
The replacement, step by step
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Park the wipers and cut the power. Switch the wipers off so they park, then disconnect the chassis battery.
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Mark the arms. Run painter's tape along each blade on the glass so you can reinstall them in the same spot.
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Remove the arms. Pop off each cap, remove the nut, and use the puller. Prying against the windshield can crack it.
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Get to the motor. Remove the panels in the way and photograph each one.
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Disconnect the motor. Unplug it, photograph the linkage, and pop the linkage off the crank arm.
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Swap the motor. Unbolt the old one and check that the new one's mounting holes and connector match. If you move the crank arm over, mark its angle first and match it exactly.
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Test, then reassemble. Reconnect the battery, run both speeds, and let the motor park. With it parked, reattach the linkage and panels, set the arms on their tape marks, and snug the nuts.
Common mistakes to avoid
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Find out what wore out the old motor. Move the linkage by hand before installing the new one. If it feels stiff or gritty, a seized pivot shaft or worn bushing will shorten the new motor's life too.
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Go easy on the arm nuts. Too much force can strip the pivot shaft threads.
Check the rest while it's apart
With the panels off, check each wiper pivot shaft for play or stiffness, look over the linkage bushings, and make sure the arm springs still hold the blades firmly. If your blades streak or are over a year old, replace them now too.
Get Your Wipers Working Again
The four checks above will find most wiper problems before you order anything. A motor that only acts up in the rain can take more than one pass to pin down. If you're not sure what to order, give us a call. The number on your old motor's label, or your year, make, and model, is usually all we need to find the correct part to fit your Newmar.
Browse our RV wiper parts to see what fits your coach.
Frequently Asked Questions
How do I know if my RV wiper motor is bad?
If about 12 volts reaches the motor plug with the wipers switched on and the output shaft still doesn't turn, the motor has failed. A motor that hums without turning, or one that moves slowly even after you've ruled out a stiff linkage, is also on its way out.
Why do my RV wipers stop in the middle of the windshield?
If they stop mid-sweep when you switch them off, check the park circuit first. The switch that stops the wipers at park sits inside the motor, so if its power feed checks out, the motor needs replacing. If they stall mid-sweep while they're running, look for a tripped breaker, a binding linkage, or a motor that's losing strength.
Can I replace an RV wiper motor myself?
Yes, if you're comfortable with hand tools and a multimeter. The motor itself unbolts easily on most coaches, and reaching it through the front panels takes most of the time. If you'd rather skip that part, a mobile RV technician can do the install with a motor you've ordered.
What's the difference between a dynamic-park and a coast-to-park wiper motor?
When you switch off a coast-to-park motor, it keeps running on its park contacts until the blades reach park, then cuts power and coasts to a stop, so the exact resting spot can drift a little. A dynamic park motor brakes itself electrically when it reaches park, which stops the blades quickly and in the same spot every time. The two are wired and controlled differently, so replace yours with the same type your coach came with.
Why do my RV wipers work on high but not low?
Low and high speed run on separate circuits, and usually through separate brushes inside the motor. Check for power on the low-speed pin at the plug. If it's there, the low-speed side of the motor has worn out and the motor needs replacing. If it isn't, look at the wiper switch, relay, or wiring.
Where is the wiper motor located on a Class A motorhome?
On most Class A coaches, it's at the front, below the center of the windshield. You'll typically reach it by removing the front cap or a front access panel, though on some models you get to it from inside, under the dash. Your owner's manual or chassis documentation will show the location for your model.
