My O-scope shows 1.7 ohms pin to pin on the male side and 2.2 at the rambo terminal.
I’d encourage everyone to power up and set their beds to something like 60 degrees science and feel the connector while it heats. You will have to de loom the wires and feel them to see if they are hot or not. On mine the connector and wires were almost immediately hot to the touch.
I had a slightly different issue that knocked my bed out last weekend. In full disclosure though I have worked on the electricals of my machine, so I may very well have caused this issue myself. The charred section was on the power leg that feeds the print bed. I notice on the newer printers (mine is electrically mostly a Taz 3) the wires have been beefed up to the next gauge up and are better quality looking copper. The heated bed cable itself seems to be fine though. I’m thinking I may have to grab some crimp pins and make a new cable anyways though.
Anyways, like I said, I’ve worked on the internals of this machine, so this is most likely not typical and is most likely user caused. But it’s a neat picture. I did pull the wire out when removing the switch, prior to that it was well attached.
I have seen a couple machines like that myself. It gets hot at the crimp joint which is where the ones I have seen are turning brown and then black. So you might solder the wires so if they do start getting hot they might melt the solder and solder themselves in the crimp. YMMV.
Good idea, I’ll give that a shot. I plan on doing some rewiring on this machine as soon as I get the second one up and running anyways to make use of my new cable hider thingies so when I get to that the bed wiring will also get done.
I looked up the parts for the bed cable itself. Digikey carries most of them, Mouser carries the rest
Housing for case and cable ends
https://www.digikey.com/products/en?keywords=206429-1
https://www.digikey.com/products/en?keywords=A25053-ND
Heated Bed pins:
https://www.digikey.com/products/en?keywords=A31997TR-ND (Anyone know the amp rating for these? they look like Molex computer PSU pins so it should be up there )
https://www.digikey.com/products/en?keywords=A31998TR-ND
(Rated up to 25amp per pole)
Bed cable plug housing
http://www.mouser.com/ProductDetail/Anderson-Power-Products/1327G6/?qs=sGAEpiMZZMtjzVbpKqo2YZRH3O%252bLIhj7YNijyfnAJ74%3d
Bed cable pins
http://www.mouser.com/ProductDetail/Anderson-Power-Products/1332-BK/?qs=sGAEpiMZZMtjzVbpKqo2YZRH3O%252bLIhj7SDquRxuuD%2fw%3d
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I’m having this issue on my Taz 5 as well
Same just happened to my TAZ5.
Printer stopped mid-print with a heat bed thermal runaway error. Purple wires fried at connector.
I know this is an old post but this just happened to my Taz4.9 exactly the same purple bed wires melted. Ill be replacing them and trying to upgrade as well, all thanks to you sourcing them. You are amazing thank you for posting that.
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You’re welcome! Glad we could help!
Just a FYI on this issue - The standard connector pins are NOT rated to carry the current going through it! The original heated bed was a 240 Watt one and they upgraded it to a 360 Watt one(arouind Taz 3 time range), So current went from 10 amps to 15 amps for a 13 amp rated connector. The reason it burns up.