can parasitic draw be caused by wrong bulb size?

[franken]

The answer to the original question is no.
A - current flow means you have the meter leads connected backwards of what the meter thinks is right. Actual current flow direction theory is up for debate, but makes no difference.
Swapping parts for no real reason wastes money. That's called shotgunning. Troubleshoot.

Electric systems are simple, but hard to figure out. A circuit is a circle from the source and back through a load. A load is something like a group of lights such as park lights or whatever. From the battery/alt the exact same current flows to and from said circuit. Its a circle. Nothing is lost or gained in the circle.
E=IR
or elecromotive force, (Volts) is equal to current times resistance. You can transform that w/ simple algebra.