Fixing a wire connected to a motor

My shopvac suddenly stopped working. It’s a month old and had some pretty heavy use during it’s short life. It felt a bit hot, so I left it for an hour, thinking there was some kind of over heating sensor that had tripped. I was only using it to vacuum the car, so it wasn’t being taxed.

My options were:
1) See if I could find the receipt, return to Home Depot, but I bought it 70+ miles away.
2) Buy a new one on Amazon with a monthly subscription for a 5% discount!
3) See if I could find out what was wrong and fix it myself with the help of Permies.

I went for option 3.

There is no sticker over a screw invalidating warranty that you find on computer gear, and the screws are all the same size - standard Phillips head into plastic.

It didn’t take long before I discovered that the wire from the switch was no longer connected to the motor - see pics. All I need to do is fix it, but I have no idea how to do it. I’m sure there are folks here who have fixed similar problems. My best guess is to snip the cable ties, investigate further, connect a new bit of wire somehow. My concern is, that looks like a pretty neat and tightly wound bundle so snipping the ties might make a big mess and I don’t have tiny fingers or dexterity to put it back together. What are your thoughts? Cheers.

Do you own a soldering iron? A little flux and a dab of solder and I believe that could be the best way to mend the broken wire with a semi-permanent repair.

James Freyr wrote:Do you own a soldering iron? A little flux and a dab of solder and I believe that could be the best way to mend the broken wire with a semi-permanent repair.

No I don’t . . . I did use one in school back in the 80’s. Might be a worthwhile investment though. Thanks James.

Don't snip the cable ties!
Try to pull the disconnected wire through the first (and maybe second) cable tie to give you some access to the conductor.
Then remove insulation until you get at least 5mm, better 1cm of conductor. Depending on what kind of conductor you find (stranded wire like the black cable) or solid core (the one where you can see the copper through the transparent, you will need to remove that transparent insulation. (scraping or fire will do that.)

After that it should be possible to twist the conductor of the black cable around the exposed conductor from the motor and insulating it with some flexible tape.

IF you can expose a bit of wire on either end I would use a wire nut. Easier than soldering and you know for sure that it will hold up. It basically screws the wires together. I always wrap electrical tape around the nut and wires too, just to be absolutely positive it will never un-twist. They come in different sizes and you are looking for the smallest one that will fit over both sides of the wire.

Soldering would totally work, I just suck at it.

I hadn't come across 'wirenuts' before and had to look them up:



source

Much like mentioned in this really great video I found a while back, I'm one of those anti crimp connector people. Mostly because it's way easier to keep a couple supplies on hand in quantity than to keep most of that stuff plus a ton of fiddly overpriced connectors well stocked. For a pro shop it's great, as a DIYer I will stick to other methods, and the points brought up in this video I think are particularly useful for this repair:



I realize a vacuum isn't a race car, but they both experience vibration. If the manufacturer had followed some of this advice you wouldn't be dealing with this issue. Having the wire unsupported and bent around before the crimp connector in a high vibration environment caused the wire to fatigue and fail. If this isn't addressed it will fail again. One trick I've been using on cars is to cut two pieces of shrink tubing, grab E6000/Amazing Goop/Shoe Goo or similar glue, and I will put glue on the solder connection to keep out moisture, short piece of shrink tubing over the repair, and then longer shrink tubing over the whole thing as a strain relief. In this case you might not have to go quite that far and perhaps just use a dab of epoxy or anything to keep that wire from flopping around, work hardening it to failure.

I agree not to cut both zip ties at the same time. It may be possible to cut the one off, lift the wire/connector up, add new zip tie, repeat on second zip tie to get it out to work on. I also will purposely flip one end of zip ties 180* so they snug things down but pull apart later, instead of fighting with the clip or ruining the zip tie.

If you have trouble fitting your hands in there it might be worth a coffee, beer, whatever to someone with appropriately sized hands for the job.

Edward Norton wrote: There is no sticker over a screw invalidating warranty that you find on computer gear

Just an FYI, in the US they passed something stating that is no longer a valid excuse for refusing warranty service or refunds. I remember maybe 20 years ago when some dealerships were refusing to replace bad transmissions because people changed to an aftermarket air filter. I bet you can still find places trying to convince people it's their fault when they touched something they "shouldn't" have touched even when the failure had nothing to do with what was touched. This goes both ways. I've seen people buying things like broken computer processors on ebay when the seller knew it was broken, it was their fault, and they sold it for parts at pennies on the dollar. They get bought up to turn around and get a free replacement and people seem to be proud of this fraud. Overall it is a net win, but between them still putting sticker on things to scare people and scammers trying to rip off businesses it still isn't a perfect situation.

EDIT - I guess with some of the confusion outside the US, this recent Great Scott video can help clear up some confusion and show the strengths and weaknesses of wire nuts vs Wago connectors:

Sebastian Köln wrote:Don't snip the cable ties!
Try to pull the disconnected wire through the first (and maybe second) cable tie to give you some access to the conductor.
Then remove insulation until you get at least 5mm, better 1cm of conductor. Depending on what kind of conductor you find (stranded wire like the black cable) or solid core (the one where you can see the copper through the transparent, you will need to remove that transparent insulation. (scraping or fire will do that.)

After that it should be possible to twist the conductor of the black cable around the exposed conductor from the motor and insulating it with some flexible tape.

Thanks Sebastian - I managed to free the “wire” - and it wasn’t wire, it was the heat shrink stuff.

Dan Fish wrote:IF you can expose a bit of wire on either end I would use a wire nut. Easier than soldering and you know for sure that it will hold up. It basically screws the wires together. I always wrap electrical tape around the nut and wires too, just to be absolutely positive it will never un-twist. They come in different sizes and you are looking for the smallest one that will fit over both sides of the wire.

Soldering would totally work, I just suck at it.

Thanks Dan - always wondered what those gizmos were called. I asked my neighbour who is an awesome horder and he gave me a spare. Job done.

Daniel Schmidt wrote:Much like mentioned in this really great video I found a while back, I'm one of those anti crimp connector people. Mostly because it's way easier to keep a couple supplies on hand in quantity than to keep most of that stuff plus a ton of fiddly overpriced connectors well stocked. For a pro shop it's great, as a DIYer I will stick to other methods, and the points brought up in this video I think are particularly useful for this repair:

Great stuff Daniel and interesting videos with some useful information. I discovered the wire had worn through because the plastic cap it was stuffed under had sharp edges and the motor has a very high rpm. I’m guessing it just wore through - my cynical 19 year old who lent me his wire strippers thinks it’s classic designed obsolescence. Made his cynical dad very happy!

I’ve fixed it for now with a wire nut which I accept is not a great solution but will do for now as I have to crack on. You are right about vibration, very valid and I’ll put together a better fix in the near future.

And thanks for all the other info . . . Good to know. My son was fixing an PC yesterday and the PSU had the ‘void warranty’ sticker.

I’m a very happy chap - you lot are awesome!

My vac is working thanks to all the help and didn’t cost me a penny. I learnt some new words for thingammy-bobs and gizmos.

If I had gone for the first option, receipt in hand, chances are, I’d walk away with a new vac and old one would go into landfill. Makes you think . . .

Edward Norton wrote:If I had gone for the first option, receipt in hand, chances are, I’d walk away with a new vac and old one would go into landfill. Makes you think . . .

And the replacement may have had the same sharp age and short life as the first one!

Job well done!

Jay Angler wrote:

Edward Norton wrote:If I had gone for the first option, receipt in hand, chances are, I’d walk away with a new vac and old one would go into landfill. Makes you think . . .

And the replacement may have had the same sharp age and short life as the first one!

Job well done!

So true!
Two caveats:
First, knowing the weakness, one could preempt the failure with a modification to strengthen it first. I've done something similar by replacing the provided cord on a circular saw*, literally right out of the box, with a higher quality and much longer cord.
Second: Keep the broken unit, go buy another exact duplicate replacement unit. Why? To take a chance on a "complimentary repair" in the future... Chances are, you break one part one the first, and a different part on the second. Lucky you with a donor unit! Now you can combine parts and get a working unit again. Plus a spare set of accessories, like wrenches, or nozzles, or whatever the thing has, for when you lose or wear out one of those.

*Seriously, who puts a 7' cord on a circular saw? A prankster engineer who giggles at the thought of you getting 1 foot from completing your cut on a sheet of plywood, and the plug hangs up on the edge of the sheet, or unplugs itself, that's who.

I only had one job in my entire career until retired - I repaired computers and their peripherals. They ranged from those inked ribbon dot matrix printers you find at cashiers through automated teller machines until  150 Amp - how shall I put it? - stuff that the client had to apply to the US government for a supercomputer licence.

Most electrical connections are crimped. There is the occasional wire nut for motors but never a Wago.

Here is my goto video for wire nuts: