There is no way to test "current available". You can measure the current used by any given device while it is in use, but the only way to determine "available", or maximum, current is to plug in higher and higher demand devices until you blow the circuit.Wise words. I seem to have difficulty measuring current with my multimeter. I know it is done in series to the circuit, but when I tried on the car wiring for the cig lighter, I got sparks. h: Any idea on the setup I installed, how I can test the current available at the AC plug? This way I can settle it once and for all and know what I can plug in or not.
I'm not sure how you got sparks check the car wiring unless you grounded the + lead, but in simple terms, you would need to connect the neutral (big) slot of the socket to the neutral pin of the plug with a short jumper wire and connect your dmm in series between the hot (small) slot of the socket and the hot pin of the plug. Not all DMM's can measure a/c amperage.
Measuring dc amperage is the same thing - you connect the DMM in-line with the + wire and the connection on whatever device.
What did the packaging for the converter you used say about either efficiency or input/output?