Need to test my new headrest monitors

I am having trouble coming up with a solution to power them up to test that they did not arrive DOA.  Somebody on another forum said to hook it up to my battery, but with no further explanation.  I'm afraid of frying my new monitors using that method.  I am a novice at car electronics.

The only idea I have come up with thus far is to splice off a cigarette lighter adapter from a car electronic product and hook up the + and - from the monitor to the appropriate wires on the adapter and plug it into the outlet of my car.  Would this work?

I appreciate the input.

I'm testing them to make sure they work as advertised as I only have a short window to return the product if defective.  I've heard of some monitors arriving DOA or with other problems.  I don't want this to happen to me.

My problem is getting the monitors power.  I don't know jack about cutting into my cars wiring system, which is why I asked about the cigarette lighter plug.  Not sure if this would work though.

I'm buying my A/V components as I can afford to buy them.  I'll have them installed professionally when I get everything I need.  But as I mentioned earlier, I need a way to verify that the items I buy work as advertised.  (I'm doing alot of Ebaying for these items, btw.)  So I hope you can understand my concern.

Thanks for the info Aggie.

Is there anything in particular I should secure the wiring to the battery and ground locations with?  ie. elec tape....