What happens now is that when you plug the fixture into this tester, the lamp will complete the circuit by connecting the hot and neurtal, thus illuminating the LED. If the LED doesn't light up, check your lamp (don't simply throw it away as there could also be a fault elsewhere in the fixture).
You could also place a LED between the resistor and Ground to test for shorts. This LED would only light up if there was a fault (I would use a RED LED).
NOTE: that this will only check lamps that are not controlled by any internal circuitry, such as inteligent lighting, strobes etc. It can be used on Par cans, Fresnels etc.
Are you referring to the actual connections or in what order the components are connected together?
I would solder the connections and use a battery clip on flying leads.
Now - in Australia, we make these using small plastic boxes with a surface mount receptacle and the LED(s) mounted into the box. The battery, wires and resistor are inside. Use either a battery clip or some double-sided tape to keep the battery from moving.
Now - in the US - you guys have more plug and receptacle types and I really have no idea as to the size, shape and configuration of them all. Looking at the GAM check on the web (and having no size reference to work from) I would imagine that you could fit it all the components into the actual receptacle. You would have to use a smaller battery and I would imagine that a 3V lithium would do the trick. If so, get one with leads or tags already on it as it is much easier to solder to them than to the battery directly.
So for a 9V battery R= (9 – 1.7) x 1000 / 20 = 365 (round up to 370) I made a mistake on my initial post when quoting the resistance, which I have now fixed.
Also, if you are unsure as to the anode (+) and cathode (-) legs on the LED, have a look at the actual plastic ‘light’ part. The flange that runs around the bottom of this will have a flat side. The flat side corresponds with the cathode.
To test it, use a piece of wire to short the Hot and Neutral connectors.
I think that whatever receptacle you use, you will have to make up adaptors if you want to use more than one type of plug.
Now – if you wanted to add the Hot to Ground short test, all you have to do is add an additional LED. To do this you would solder the anode of the second LED to the resistor, at the same point to which the first LED connects. The cathode of the second LED then connects to the Ground pin on the receptacle.