If your Karcher pressure washer has stopped working and you've managed to identify the faulty part, you'll need to replace the part to get your pressure washer up and running again. In this article, we'll guide you through replacing Karcher pressure washer electrical parts step by step so you can return your appliance to working order. The steps to these replacements may vary depending on your model of pressure washer, but the steps should generally be similar.
If your pressure washer seems to be suffering from an electrical problem and you haven't been able to identify it yet, however, don't worry! Our article on how to diagnose pressure washer electrical problems will help you in no time.
What you will need
- Torx screwdriver
- Flathead screwdriver
- A replacement of your faulty part
Finding your model number
When replacing a certain part from your pressure washer, you will first need to know your appliance's model number and information. This will help you purchase the correct part for your specific appliance. If you aren't sure what this information is or how to find it, don't worry! Our article on how to find a Karcher pressure washer model number is here to help.
Replacing Karcher pressure washer electrical parts
Now let's get stuck in! To learn how to replace Karcher pressure washer electrical parts, either watch our video or follow our step-by-step guide beneath.
For your own safety, always make sure you switch your appliance off and unplug it from the mains before carrying out any work, repairs or part replacements.
Accessing the pressure washer's interior
Step 1: Opening the pressure washer
To carry out any of these fixes, you will first need to disconnect and remove any hoses or accessories that may be on the outside of the pressure washer. You will then need to separate the two halves of the pressure washer's body by unscrewing the seven screws that hold it together using a Torx screwdriver.
Once the screws have been removed, you can go ahead and separate the two halves.
Step 2: Removing the motor
Now you will be able to see the motor and its casing, which will need removing. First, remove the detergent hose from the end of the motor assembly.
Then release the mains lead and grommet from the casing.
You can then lift the motor out of the cover. When you place the motor down on a surface, make sure you don't lean it on its switch lever. Instead, lay it down so the switch lever is pointing upwards.
Step 3: Removing the motor casing
Next, you will need to separate and remove the motor casing. You may need to use a flathead screwdriver to release the clips that keep both halves of the casing connected.
The top half of the casing will come free easily, but you may find that there's a little black clip keeping the bottom half connected. Give this clip a press with your flathead screwdriver and it should release the bottom half of the motor casing.
Replacing the switch
You should now have your motor before you with all of the casing removed.
Now let's take a look at removing a faulty switch. To do this, simply give the switch a good pinch and work it out of the motor assembly.
You will need to reuse the switch lever on the new switch, so turn the lever 180 degrees and it should come out of the switch assembly.
Then fit the switch lever onto the replacement switch and twist the lever into place.
With the lever connected to the new switch, you can then fit the new switch into place on the motor assembly.
You can then disconnect the electrical connections from the old switch and connect them to the new switch. Take note of where the connections go in the old switch, as they will need to connect into the same places on the new one.
Replacing the carbon brushes
Another common electrical part that may need replacing is the carbon brushes on the motor.
These are held in by a small spring, so simply ease the spring to one side. This will allow you to remove the carbon brushes.
You can then disconnect the carbon brushes from the motor by pulling off their electrical connectors.
To refit your new carbon brushes, slot them back into place, making sure the small spring is out of the way as you do so. Once a carbon brush is in place, you can then connect its electrical connector too.
Putting the pressure washer back together
Step 1: Reassembling the motor casing
Once you've replaced the switch and/or the carbon brushes, you can put the pressure washer back together again. Start by placing the motor back into the bottom half of the casing, making sure the switch and the capacitor fit into their slots as you do so.
Make sure the wires and the mains cable are tucked into the groove so they don't get pinched or trapped by the motor casing.
You can then slot the top half of the casing over the motor assembly and fit the casing back together, making sure the clips are all secure.
Step 2: Refitting the motor
Now you can place the motor assembly back inside the pressure washer casing.
When you do this, make sure the mains grommet goes back into the right place, as pictured below.
Step 3: Fitting the pressure washer back together
Before fitting the two halves of the pressure washer casing back together, first remember to reattach the detergent hose.
When you place the top half of the casing over the motor, pull the hose all the way through its small opening.
You can then screw the pressure washer body back together by refitting the seven screws you removed earlier.
Replacing the capacitor
Step 1: Accessing the capacitor
If you own a larger model of pressure washer, it may be the capacitor that's faulty and needs replacing. Again, you will need to open up the appliance to access the capacitor. First, remove any hoses or accessories that might be connected to the outer body. Then turn the pressure washer upside down and remove the 10 screws that keep the pressure washer casing connected with a Torx 10 screwdriver.
Once the screws have been removed, turn the pressure washer back over, making sure to keep the two halves closed together as you do so.
You can then lift off the top half of the casing (the yellow half), making sure that the mains lead is out of the way.
You will then be able to see the motor and pump assembly inside the appliance. You can lift this up and out of the appliance, placing it upright on whatever surface you're using as pictured below.
Then disconnect the detergent hose by pulling it off and placing it aside.
Step 2: Removing the old capacitor
You will then be able to see the capacitor. The capacitor is only held in place by the housing, but it is also pinched by the motor at the bottom of the assembly and the pump at the top of the assembly.
You will need to unscrew the four bolts at the top of the motor and pump assembly. However, you only need to fully remove the two bolts from the side closest to the capacitor first, as indicated below.
The two bolts on the other side simply need to be loosened as much as possible.
Using a ratchet, loosen and remove these bolts.
This will create a gap in the motor, allowing you to pull the capacitor down and away from the lip to remove it.
When a capacitor has failed, it will leak as a result. As you can see in the picture below, the capacitor has failed significantly, so it will need to be replaced with a new one.
Step 3: Fitting the new capacitor
When fitting the new capacitor, line up the connectors nice and straight. You should feel them fit into place when you slot the new capacitor into the housing.
You can then push it the capacitor up another couple of millimetres to secure it in place, pushing it over the lip.
You can then return and secure the four bolts back into the top of the assembly, making sure they're nice and tight. You may need to use a ratchet for some extra force when tightening the bolts.
When you're screwing the bolts back into place, make sure the gap in the motor housing has closed...
Make sure the capacitor is in the correct position...
And make sure the water seal is covering the join between the capacitor and its housing.
Step 4: Reassemble the appliance
To start reassembling the pressure washer, place the motor and pump assembly into the bottom of the pressure washer casing. When you do this, take note of the mounting hole pictured below...
And make sure this fits together with the correct part of the motor and pump assembly.
Once the motor and pump assembly is in place in the bottom of the pressure washer casing, you can reattach the detergent hose.
Then make sure the mains cable grommet slots into the correct place inside the yellow casing.
Also, make sure the mains cable is tucked under the capacitor.
You can then slot the top of the pressure washer casing back onto the appliance.
Then, holding the two halves of the pressure washer casing together, flip it over and screw it back together with the 10 screws you removed earlier.
And there you have it! How to replace faulty Karcher pressure washer electrical parts. Hopefully, your appliance should now be up and running properly once more!
While you're here, why not also make sure you're using your pressure washer as safely as possible? Doing so will help you prevent future faults with your appliance, as well as helping you avoid any safety risks or hazards. Our article on important safety checks for your pressure washer has all the information you need.
Before you go, don't forget to also sign up to our mailing list below. Doing so will ensure you receive important eSpares advice and content related to appliance care and repairs, as well as exclusive discounts!