Is there a USB splitter available to separate charge/data functions?

I am using the cable that came with the iPod. Also am connecting to a standard USB power adapter that Apple provides with the iPod. When I connect it to external power source (AC Mains), it powers on and works. It also shows me that the battery is fully charged. I don’t know what happens when I connect it to say a Mac or PC in the USB port. It does not come on, the screen flashes dimly and very infrequently. Obviously it is not noticed by ITunes running on Mac or PC in this case. That is why I am looking for some way of connecting AC Mains power and Mac/PC USB port at the same time to this iPod. Any suggestions welcome.

I don't think s splitter will help you here. Apple never offered one as its just not needed. You have a problem either with the cable or your PC system. I think is better to fix the problem than trying to walk around it. Keep in mind if the iPod cable is bad then a splitter won't fix anything as the problem is still present.

At this point I would get a new cable to see if that fixed the issue or you could try testing your PC systems USB ports using this tool USB Mini Voltmeter comparing what is happening between the iPod charger and the PC/Mac USB ports.