Melted dishwasher wiring.

Reply

  #1  
Old 08-14-13, 05:08 AM
Member
Thread Starter
Join Date: Aug 2009
Location: USA
Posts: 4,941
Melted dishwasher wiring.

I found this melted wiring inside my dishwasher this morning: Dishwasher Wiring | Flickr - Photo Sharing! . Those are the main power wires that have melted. I believe the last repair I made was to replace the fuse and it included the yellow wires and that connector that is all melted. I have no idea what went wrong there.

My idea to fix this is to remove the damaged wiring and reconnect with butt connectors and wrap with electrical tape. Any thoughts on this?
 
Sponsored Links
  #2  
Old 08-14-13, 07:42 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: NJ - USA
Posts: 43,494
Is that a plug where the black wires join the yellow wires ?
Looks like one or both of the pins was loose.

Instead of using butt crimps.....use cap crimps.

Name:  cap crimp.jpg
Views: 1176
Size:  6.7 KB
 
  #3  
Old 08-14-13, 07:55 AM
Member
Thread Starter
Join Date: Aug 2009
Location: USA
Posts: 4,941
That is not a plug. Each of those round things on top are set screws. The wires go in and are held down by the screws.
 
  #4  
Old 08-14-13, 10:31 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,213
It looks as if the setscrew connection has failed. I'd use the crimp connection.
 
  #5  
Old 08-14-13, 11:47 AM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
Droo, I think I'm seeing exposed copper in the yellow wire with the most damage. I also think I'm seeing a burn mark on the inside of a panel near there, and I'm guessing those are related. You said that you replaced the yellow wires at some point, IIRC. It looks like what happened this time is that the insulation on the heavily damaged yellow wire failed, either because it was cracked to begin with or because it became damaged with use, most likely from rubbing against a surface that abraded it.

You're going to need to replace those wires again, obviously. When you do, I wouldn't have any hesitation about replacing the melted terminal block with another one just like it, or using butt splices as you suggested. Cap crimps are great when the two stripped conductors are facing the same direction, IMO. When they're facing each other, particularly when there's a limited amount of space to fit everything in, I go with connectors that install inline with the wiring - butt splices and terminal blocks.

You'll need to replace every bit of wire that has damaged insulation, either cutting it back to where it's obviously good or replacing it entirely. As you put everything back together, pay particular attention to the insulation on the wiring. make sure it's all in good condition. Also fit all of the wiring in so that it's away from other parts. Keep it midair as much as you can.

If you use a cable tie again, be sure to cut off the part after the lock. I would use a bit of good electrical tape to bundle the wires instead. I wouldn't use tape to cover the splices, because it shouldn't add any protection and it's just another thing to hold heat in the wires. Cool wires are your friend, so I'd go easy on the tape.
 
  #6  
Old 08-14-13, 12:14 PM
Member
Thread Starter
Join Date: Aug 2009
Location: USA
Posts: 4,941
I didn't find the crimp caps at HD so I got some of those push in connectors. I cut off all the wire that had damaged insulation.

I think the problem was the connector block. There was a high resistance short there that cause the wires to heat up. Insulation from the black wires melted into the connector block itself. The yellow wires also lost insulation.

There isn't much for these wires to rub against. They just hang in the empty cavity of the door.
 
  #7  
Old 08-14-13, 12:48 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
I didn't find the crimp caps at HD so I got some of those push in connectors.
The wiring in your dishwasher should be, and looks like it is, stranded. If so, I don't know of any push-in connectors that are rated to connect those. I would use the butt splices, preferably, or just twist-splice and wire-nut them, instead.

I cut off all the wire that had damaged insulation.
The conductors themselves may be damaged, even inside insulation that appears to be good. What did the strands look like when you stripped them? Were they bright, shiny, flexible and indistinguishable from those in a new piece of wire, or were they kinda orange, dull and stiff or even brittle?
 
  #8  
Old 08-14-13, 12:58 PM
Member
Thread Starter
Join Date: Aug 2009
Location: USA
Posts: 4,941
The push-ins accept stranded.

The wire was a bit dull but was flexible.
 
  #9  
Old 08-14-13, 01:49 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
Cool. So is it fixed now?
 
  #10  
Old 08-14-13, 04:08 PM
Member
Thread Starter
Join Date: Aug 2009
Location: USA
Posts: 4,941
Yeah. I ran a cycle and everything seemed ok. I may pop it back open to double check the wire condition though.
 
  #11  
Old 08-14-13, 05:19 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
Sounds like you got it. Never hurts to double-check, of course.
 
  #12  
Old 08-15-13, 07:58 AM
Member
Join Date: Mar 2010
Location: USA
Posts: 2,855
The most common reason for wires with melted insulation is a loose or bad connection at the end of the wire (or another wire connected to the same terminal block). If you are working on some wires and an end is oxidized, you need to clean or scrape the end to shiny metal before making the connection.

It is usually easier to snip off the end of stranded wire and strip off a little more insulation to expose a new end, rather than scrape the strands clean.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
'