How to Replace the Switch on a Makita Grinder

Glitch in your grinder switch? It's time to face the fix. Whether you are a master mechanic or a garage-based grinder, eReplacementParts.com provides the parts, procedures and facts you need to fearlessly fix what fails you.

The switch assembly on many Makita grinders is made up of three components: the plastic (external) switch button, the (internal) switch lever, and the (internal) mechanical switch itself. The mechanical switch on your grinder may get cycled on and off hundreds (if not thousands) of times before it finally wears out and fails.

Symptoms of a bad switch can be a grinder that simply won't turn on. Or a grinder that turns on, but loses power intermittently during use. Replacing the internal switch is very easy to do.

This article provides step-by-step instructions for removing and installing the switch on a Makita grinder.

Let's get started.   REMOVING THE SWITCH [top] 1. Remove the side handle.

Unscrew and remove the side handle from the grinder.

  2. Remove the guard.

Loosen the lock-screw on the guard assembly.

Rotate the guard assembly to disengage it from the housing.

Remove the guard from the grinder.

    3. Remove the rear cover.

Remove the (1) screw from the rear cover.

Slide the rear cover away from the motor housing.

  4. Remove the strain relief strap.

Remove the (2) screws from the strain relief strap.

Remove the strain relief strap from the grinder.

  5. Remove the switch.

Use long-nosed pliers or a screwdriver to disengage the switch lever from the button on the switch.

Pull the lock-tab away from the switch assembly.

Use adjustable pliers to lift the switch assembly out of the motor housing.

Note the configuration of the switch and cord wires. (This will ensure accurate installation in later steps).

Loosen the (2) terminal screws and remove the power cord wires from the switch.

Remove and reserve the terminal screws for use on the new switch.

Disconnect the (2) field wires from the switch (these are typically red).

    INSTALLING THE NEW SWITCH [top] 6. Install the switch.

Connect the (2) field wires (red) to the new switch.

Connect the power cord wires to the switch terminals.

Secure the cord wires to the new switch with the (2) screws.

Position the cord wires alongside the switch assembly.

Install the switch assembly into the motor housing.

Verify that the lock-tab engages the switch assembly.

Re-connect the switch lever to the switch button.

  REASSEMBLING THE UNIT [top] 7. Reinstall the strain relief strap.

Install the strain relief strap.

Secure the strain relief with the (2) screws.

  8. Reinstall the rear cover.

Visually inspect the wires for potential “pinch-points” and adjust/tuck the wires as necessary.

Slide the rear cover onto the motor housing.

Secure the rear cover with the screw.

  9. Reinstall the guard.

Install the guard assembly onto the grinder.

Rotate the guard assembly to engage the mounting plate.

Secure the guard with the (1) screw.

  10. Reinstall the side handle.

Install the side handle onto the grinder.

Tighten the side handle until secure.

You can't place a value on a job well done, unless you did it yourself. (Which you did.) Now you can place that value back into your own pocket. (Or into your business.) Not only did you refine your grinder at a fraction of the cost of replacement; you have expanded your skills far beyond the daily grind.

Find your next grind here.   [top]