XMSJSIYUSB 2.0 Female Pigtail Cable Extension Power Cable 22AWG 5V 3A USB A Socket to 2 Pin Bare Wire Open End Connector for DIY-2 Pcs (0.3M) PLS Test The Neg and Pos Before use

I used these to create a permanent USB powered connection for my dash cam. I found the red and black wires were reversed. Black wire went to the VCC+ contact on USB connector and red wire went to the ground contact. Luckily I tested before I hooked up my device and gave it reverse voltage. I reversed the wires by hooking the black wire to my +5 DC source and red to ground and then it was the correct polarity. When I inserted my USB A Male cable, the contacts wouldn't touch inside the USB connector. I had to give it a good bend to get the contacts to touch the USB. I definitely would avoid these due to flagrant quality issues.

It's a good thing I tested these before trying to put them to use. The polarity of the wires is backwards. Had I connected something to one of these, it would have been destroyed immediately.

This is sold as a power cable. USB power is 5 vDC. For the majority of DC wiring, red is positive and black is negative or common. These are just the opposite. Be sure to confirm wiring with a continuity tester before connecting.As with many chinese components, these are probably seconds or from the reject bin.

Wires are backwards red negative black positive but worked fine if hooked up correctly.

The red and black wire are opposite apparently. I hooked this up to my 12v fuse panel in my car. It broke my phone when I tried to charge it. There is no label or paper work that shows a diagram of the wiring. Apparently this is set up for “reverse polarity” which will damage anything hooked up to it.

lucky I didn't blow anything trying to troubleshoot tho. works well otherwise though.

As many others have written - BOTH of the cables I received DO NOT follow red=+5 black=gnd conventions. In my case I saw other folks reviews and compensated before I damaged any of my equipment.

The media could not be loaded. This is NOT wired correctly for DC voltage. The black wire is connected to the positive terminal of standard USB ports. I wired this do an rgb controller and instantly shorted it. I'll be seeking compensation for this flaw. Completely unacceptable.

This is a pair of 2 wire USB power cord cords with female USB A sockets. I had read that others had reported that the black wire was carrying the +5V DC rather than the red as you'd expect. However, you never know if this was a bad batch that was since corrected, so I tested with a USB tester and sure enough the problem persists. Cable works just fine as long as you wire it up correctly.

Wired to fuse box in car. Didn’t work. Not sure this is meant for 12 volts :(

Works but reversed polarity !