Switching & protectionRebuild shelfHand tools, works as-is

Panel switch

Also called rocker switch, toggle, automotive switch, trigger switch.

A human-sized switch. Tool triggers are often a switch plus a potentiometer. Car switches are 12 V and stamped with a current that assumes a lamp or a relay, not a starter.

If you are new to this category

A switch opens or closes a circuit. Some switches are for your finger. Some open when they get too hot and stay open. Those do not reset. A relay is a switch that a small current turns on so it can control a larger current. Use the rating printed on the part.

Click it and listen. Then use a meter on continuity, which beeps when the contacts touch. Do not guess that a small switch can run a motor.

The three legs of a snap switch

Common is the moving contact. NO means normally open: that leg connects only while you press. NC means normally closed: that leg is connected until you press. Click the button while the meter is on continuity and write down which beep matches which leg.

Mains voltage. Line voltage, and the DC bus just after the rectifier, both kill. A disconnected cord is not a discharged supply.

Specification. The right-hand column is what is typical. The label on the part in your hand wins if they disagree.
What to look for	Usual figure
Mains rocker	Look for the current at 250 VAC. A lighted rocker may have a neon that only works on mains.
Tool trigger	Mains tools use a triac and a pot. Cordless triggers are a pot and a small switch into the controller, not a switch that carries motor current.

Volts are electrical pressure, amps are how much current is flowing, and ohms are how hard the part resists that flow. A higher voltage than the part was built for is how salvage parts die on the bench. If a cell in the table says “read the stamp”, that stamp is the whole specification.

What people actually use it for

Power switch on a rebuilt tool
12 V control panels

Leave this one when

The rocker is cracked or the mains one is only marked for 12 V. Do not 'upgrade' a low-voltage switch onto line voltage.

Buying a new one is the better idea when

Anything that is the only thing between a person and the mains, if the salvage switch has no legible rating.

How to tell if this one still works

Beep each throw. Wiggle it; intermittent contacts get worse, they do not heal.

Tools you will want: Meter.

Words on this page

Short meanings, so the rest of the entry is readable if you are not already doing this every weekend.

mains: Ordinary household wall power. It can kill. Unplug before you open anything that used it, and do not experiment on live wiring.

Where people actually find it

14 notes, most useful first. “Leave it” means the part is in that machine and you should not take it: it is dangerous, worn out, or only useful if you already know that exact repair.

Harvest at a glance
From	Call	How many	How often	Where it sits
Electric kettle	Worth it	1	usually	The click lever.
Blender	Worth it	1	usually	The front.
Hair dryer	Worth it	1	usually	Handle.
Desk or box fan	Worth it	1	usually	The speed switch.
Space heater	Worth it	1	always	The control.
Paper shredder	Worth it	1	usually	Auto / reverse.
Power strip	Worth it	1	usually	The end.
Flashlight	Worth it	1	usually	The tail.
Doorbell	Worth it	1	usually	The button.
End-of-life car	Worth it	several	usually	Dash and doors.
Motorized toy	Worth it	1	usually	The top.
Toaster and toaster oven	Bonus	1	usually	The lever.
Window air conditioner	Bonus	1	usually	The control.
Treadmill	Bonus	1	usually	The safety key.

Worth pullingElectric kettle1 · usually
In this particular machine
Mains, with the neon or LED.
Where to look
The click lever.
How to get it out
Test.
The condition to expect
Good.
Worth pullingBlender1 · usually
In this particular machine
Multi-position mains switch, sometimes with a triac on later models.
Where to look
The front.
How to get it out
Map the speeds.
The condition to expect
Contact wear is the failure on cheap ones.
Worth pullingHair dryer1 · usually
In this particular machine
Heat and speed. Mains.
Where to look
Handle.
How to get it out
Map it.
The condition to expect
Good.
Worth pullingDesk or box fan1 · usually
In this particular machine
Several taps, or a pull chain.
Where to look
The speed switch.
How to get it out
Map the taps.
The condition to expect
Contact wear.
Worth pullingSpace heater1 · always
In this particular machine
Mains.
Where to look
The control.
How to get it out
Map it.
The condition to expect
Good.
Worth pullingPaper shredder1 · usually
In this particular machine
Mains, sometimes a momentary reverse.
Where to look
Auto / reverse.
How to get it out
Map it.
The condition to expect
Good.
Worth pullingPower strip1 · usually
In this particular machine
Mains, often lighted.
Where to look
The end.
How to get it out
Read the rating.
The condition to expect
Good.
Worth pullingFlashlight1 · usually
In this particular machine
A clicky switch.
Where to look
The tail.
How to get it out
These are useful and annoying to replace.
The condition to expect
Contact wear.
Worth pullingDoorbell1 · usually
In this particular machine
A simple contact, sometimes lighted.
Where to look
The button.
How to get it out
The light is across the contacts and only works in the circuit.
The condition to expect
Good.
Worth pullingEnd-of-life carseveral · usually
In this particular machine
12 V, lighted.
Where to look
Dash and doors.
How to get it out
The lamp is often a small wedge bulb or an LED.
The condition to expect
Good.
Worth pullingMotorized toy1 · usually
In this particular machine
A slide switch.
Where to look
The top.
How to get it out
Test.
The condition to expect
Good.
Bonus, if you are already in thereToaster and toaster oven1 · usually
In this particular machine
Mains.
Where to look
The lever.
How to get it out
Test.
The condition to expect
Good.
Bonus, if you are already in thereWindow air conditioner1 · usually
In this particular machine
Fan speeds.
Where to look
The control.
How to get it out
Map it.
The condition to expect
Good.
Bonus, if you are already in thereTreadmill1 · usually
In this particular machine
A magnetic key or a simple switch.
Where to look
The safety key.
How to get it out
The magnet is part of the interlock.
The condition to expect
Good.