Smoke and carbon monoxide detectors which are powered by an AC circuit in your house rather than batteries are superior. Each one is connected to a signal wire to set off other detectors in your home if one senses trouble. The AC power is reliable and often there is battery backup if you lose power. In this video I troubleshoot a circuit meant for smoke detectors that was abandoned by a previous owner. We'll figure out if there is power and if the signal wire is still good. Then I'll show how to connect new hardwired detectors.

►For more about how to use a meter:    • How To Use A Digital Multimeter Aroun...  
►To purchase:
https://amzn.to/3u5x6Bf (Kidde hardwire smoke/co detector)
https://amzn.to/3nysT6G (Kidde 2pack hardwire smoke/co detector)
https://amzn.to/2S6otbA (First Alert hardwire smoke/co detector)
https://amzn.to/3nCgY8e (inexpensive multimeter)
https://amzn.to/2QLyJFQ (noncontact voltage meter)