When the engine is cold, W should be grounded. Regardless of the key position. If you hooked the test bulb to battery - it should light up immediately, if after ignition, it will light up when you turn the key to ignition - does not matter, as long as W is grounded, which it should be with cold engine. In real work, not test conditions, G is powered when cranking, but for the test if W has the ground, it does not matter.