The extension cables are for CPU, where the 12V lines are on the same side as the clip and are yellow too, so the polarity was not wrong.
But when I stripped the cable at the end to go into the connector the wires inside looked really thin and flimsy. The markings on the cable says 18AWG and 80 degrees, but I have a 18AWG cable and the wire inside is really think compared to these.
Yeah, Do not use those. You got ripped off by One Hung Lo mfg co. I had bought some PCI extender cables, when I stripped it there were ONLY 5 TINY STRANDS of copper inside the wired labeled 18AWG! They were more like 26AWG. I took them back to microcenter and finally got my money back after making a stink of the safety hazard these posed. Dont go cheap on extender cables, sadly, you cannot trust those off brands, they can burn your house down. Maybe
Cablez can make some for you?