If it's just a one-shot test, and you're not making any more, why don't you just borrow a meter? Walk into a local electronics repair shop, if you're friendly and buy some shrink tubing or something they'll probably check them out for you for free. If you're on the brink of getting into electronics as a hobby, though (making your own cables, you are teetering!) then invest in a decent meter. My first meter was a Sears Craftsman branded Fluke, I forget the model but it did volts, amps and ohms and was less than 100 US dollars. There are cheaper Flukes on eBay, do your research though, Fluke makes a ton of different models that do things you probably won't ever need. I have a Fluke 87v now, it was pricey but it does capacitance and is very accurate, and I use it for working on my house, my car, my computer, the guitars I build, and now on my rapidly developing audio habit. A good meter, properly used and with the occasional professional calibration, will last a very very long time. As my dad told me, "you buy good sh*t once."