How to Fix a Defective Light Switch
Posted by Scott Pendlebury on 25 May 2013
You flick the light switch to light a darkened room, and nothing happens. The problem is usually a dead bulb. Replacing this with an LED globe can make this your last trip up there. However if a replacement doesn't do the trick and the circuit breaker isn't tripped, you've probably got a blown switch.
If you're a complete novice when it comes to the electrics, hiring a qualified electrician is the safest way to get your home's spark back without getting shocked.
Before you begin working:

Turn off the power to the circuit at the fuse box
Take off the cover plate and check the wires with a circuit tester to make sure no power is running through the lines
Any one of the following problems could be causing the issues with your light switch:
Loose wire connections cause most switch problems. Make sure wires are securely attached to the switch. Screws should be tightened enough to keep wires securely in place.
Wires that are frayed, bent or nicked may not provide a decent connection. Trim the wire ends and strip the plastic sheath until one inch of wire is exposed. Reattach the wires.
Bare wires touching the electrical box will trip the circuit breaker or blow a fuse. If this is the case, check the wires have enough plastic sheathing to protect them.
Switches, like other mechanical fixtures, will break. Over time parts will wear out, so the entire switch unit will eventually need replacing.
Remember, a cracked light switch could allow damp to reach the conductors so it will need to be replaced as soon as possible.

Replacing a damaged switch is a matter of connecting the existing mounting box; otherwise you will have to replace both parts of the switch. If you are able to use the box, attach the new face plate with the old machine screws. You can then be guaranteed of having screws that match the threads.
The purpose of this advice blog is to provide homeowners and private landlords with general guidance and useful tips only. It doesn't necessarily deal with every important topic or cover every aspect of the topics with which it deals and might not be relevant or appropriate in all circumstances. It is not designed to provide professional advice or financial advice and should not be relied on as such.
If you're a complete novice when it comes to the electrics, hiring a qualified electrician is the safest way to get your home's spark back without getting shocked.
SAFETY FIRST
Before you begin working:

Turn off the power to the circuit at the fuse box
Take off the cover plate and check the wires with a circuit tester to make sure no power is running through the lines
WHAT TO LOOK FOR
Any one of the following problems could be causing the issues with your light switch:
Loose connections
Loose wire connections cause most switch problems. Make sure wires are securely attached to the switch. Screws should be tightened enough to keep wires securely in place.
Damaged wire ends
Wires that are frayed, bent or nicked may not provide a decent connection. Trim the wire ends and strip the plastic sheath until one inch of wire is exposed. Reattach the wires.
Bare wires touching the electrical box
Bare wires touching the electrical box will trip the circuit breaker or blow a fuse. If this is the case, check the wires have enough plastic sheathing to protect them.
Cracked light switch
Switches, like other mechanical fixtures, will break. Over time parts will wear out, so the entire switch unit will eventually need replacing.
Remember, a cracked light switch could allow damp to reach the conductors so it will need to be replaced as soon as possible.

Replacing a damaged switch is a matter of connecting the existing mounting box; otherwise you will have to replace both parts of the switch. If you are able to use the box, attach the new face plate with the old machine screws. You can then be guaranteed of having screws that match the threads.
Important
The purpose of this advice blog is to provide homeowners and private landlords with general guidance and useful tips only. It doesn't necessarily deal with every important topic or cover every aspect of the topics with which it deals and might not be relevant or appropriate in all circumstances. It is not designed to provide professional advice or financial advice and should not be relied on as such.
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