Help - Wires supplying power to GPUs keep melting

[jchi18]

When I first hooked up my system, I connected two GPUs onto one power cord coming from power supply.  After a little while, it melted and thought "oh shit, I shouldn't put two GPUs onto one wire."  So I separated them thinking that was the problem.  I just noticed that the wires to one of the GPUs is melted again.  I am surprised at that.  Does anyone know why this keeps happening?

I am using Corsair RM 750 power supply to power MB and 2 GPUs.  When watching killawatt, I noticed that power was steady in the upper 600s like 670-690.  I am using 2 sapphire 7950s.  What am I doing wrong?

[vm1990]

which cables are melting the atuall psu cables or some cheap ass adapters?

[jchi18]

which cables are melting the atuall psu cables or some cheap ass adapters?

the cables that came with the psu.  specifically, the ones that power the gpu.

[DrG]

The only time I had PCIe connectors melt was when somebody spilled some water onto a cable and it shorted/arc.  I would reseat the cards and check contact points.