Fixing a Kenmore Vacuum That Won't Turn
One day, after using my old Kenmore Canister Vacuum cleaner, its motor would not turn off, even though I flipped the switch to the off position. The only way to turn off the vacuum in this state is to pull the plug, which causes sparking at the outlet because the motor is a big inductor.
This vacuum has the on-off switch built into the hose handle so that it is easy to turn on and off. This vacuum is actually made by Panasonic, and has been super reliable for the 10+ years that it has been in my family. This repair guide should apply to many vacuums made by Panasonic, and other manufacturers.
After some debugging, I found that the problem is a high amperage relay inside the vacuum canister that welds itself together from repeated on-off cycles. This actually happened twice to our vacuum. The first time this happened in 2007, I replaced the relay with an Omron 25A contact / 120VAC coil relay that I found on Mouser; it fit perfectly, and is the relay pictured below. Unfortunately, Omron discontinued that model of relay, but I bet something like this relay on Amazon would work just fine if you use the normally-open terminals.
Eight years later in 2015, the relay got stuck again; this time I decided to service the relay instead of replace it. After opening up the relay, I confirmed that the contacts welded themselves together from repeatedly turning the vacuum on and off, which causes arcing and enough heat to eventually melt the contacts together.
To repair the relay, I used a screwdriver to pry the contacts apart, and then used sand paper to sand off the carbon build up on the contacts and to remove the melted bits of the contact. After the contacts were clean and shiny, I put the relay back together and tested it out. We've been using the vacuum for a few months since then, and the repair has been holding up. It might not hold up as long as a brand new relay, but it should hold up for a while, and I can just repair the relay again if it melts again.
This vacuum has the on-off switch built into the hose handle so that it is easy to turn on and off. This vacuum is actually made by Panasonic, and has been super reliable for the 10+ years that it has been in my family. This repair guide should apply to many vacuums made by Panasonic, and other manufacturers.
After some debugging, I found that the problem is a high amperage relay inside the vacuum canister that welds itself together from repeated on-off cycles. This actually happened twice to our vacuum. The first time this happened in 2007, I replaced the relay with an Omron 25A contact / 120VAC coil relay that I found on Mouser; it fit perfectly, and is the relay pictured below. Unfortunately, Omron discontinued that model of relay, but I bet something like this relay on Amazon would work just fine if you use the normally-open terminals.
Eight years later in 2015, the relay got stuck again; this time I decided to service the relay instead of replace it. After opening up the relay, I confirmed that the contacts welded themselves together from repeatedly turning the vacuum on and off, which causes arcing and enough heat to eventually melt the contacts together.
To repair the relay, I used a screwdriver to pry the contacts apart, and then used sand paper to sand off the carbon build up on the contacts and to remove the melted bits of the contact. After the contacts were clean and shiny, I put the relay back together and tested it out. We've been using the vacuum for a few months since then, and the repair has been holding up. It might not hold up as long as a brand new relay, but it should hold up for a while, and I can just repair the relay again if it melts again.
