The old electric Mulchers I come across usually have a red overload switch on the motor and a different switch on a longer wire , sometimes the other switch could be a circuit breaker but from memory I think it was a Safety Interlock Switch
Purpose: Protects you, not the motor.
Function: Prevents the motor from running when the chipper’s hopper, funnel, or access door is open.
How it works: The switch must be closed (pressed ) for the circuit to complete. If you open the funnel to clear debris or service the blades, it opens the circuit so the motor cannot start — even if you press the power button.
The switches are bypassed easily or you can hold them in for testing. But you must be careful not to injure yourself or others.
Red switch = overload reset switch ,thermal overload protector.
The Other Switch (on a long wire) = it’s a safety interlock switch, designed to prevent the motor from running when the hopper or funnel is open. This protects people.
**⚠️ You are NOT meant to bypass or hold the red switch in for safety reasons.** With these Cheap motors I've just sticky taped the switch in so it can't work as a safety switch , but What Happens if You Tape or Bypass the Red Reset Switch
You remove the motor’s only temperature protection.
The thermal protector reacts to heat inside the motor windings, which your household fuse or breaker cannot sense.
So if the motor overheats, nothing will cut power — it will keep running until the windings burn out, possibly causing smoke or even fire.
I keep an eye out for the motor and don't get the motor too hot or overload the motor if I bypass the safety switch so it's at at your own risk if you bypass the thermal overload switch and I wouldn't let anyone else use the motor if I bypass the safety switch.
I've never had a problem bypassing the switch but I keep an eye of the motor temp and a replacement switch may not be that expensive.
Also if the motor stalls or jams up with branches you would need to cut the power straight away so it doesn't burn out with the switch bypassed.
**⚠️⚠️⚠️ THERE ARE SOME SAFETY CONCERNS WHEN BYPASSING THE OVERLOAD SWITCH ⚠️⚠️⚠️** It's always recommended not to bypass the safety switch but should be fine to test if that's your problem with the stop start operation.
The following is just a universal guide to checking the red overload switch.
🧰 Step-by-Step: Testing and Replacing the Red Reset Switch
Unplug the machine completely. Safety first — disconnect it from mains power.
Let the motor cool down if it’s recently tripped. It may reset automatically after cooling, so see if it “clicks” back in first.
Inspect the switch physically.
Look for signs of heat damage, corrosion, or a burned smell.
Wiggle gently — it should feel firm, not loose or melted.
Test the switch with a multimeter.
Disconnect one wire from the switch.
With the button pressed in, you should have continuity (a closed circuit).
When it’s tripped (button popped out), it should be open (no continuity).
If it doesn’t behave like that, it’s faulty.
Check for the cause of tripping before replacing it. A switch that trips often usually points to an underlying issue:
Overload or jammed blades
Worn bearings (motor working too hard)
Dull chipper knives
Undersized or long extension cord (causing low voltage)
Blocked motor cooling vents
Replace with the exact same rated part.
Use the correct thermal protector rating (°C and Amps) for your motor.
These are inexpensive and often mounted with simple spade terminals.
Make sure connections are tight and insulated properly.
