Since you installed the 500 Amp shunt, .2 = 200 mA. 1000 mA = 1 Amp
From Bill Darden's Battery FAQ:
"Connect a 12-volt bulb across the positive and negative battery terminals to test the bulb and the battery. If it glows brightly, then remove the negative battery cable and connect the bulb in series between the negative battery cable terminal clamp and the negative battery terminal. If the bulb continues to glow brightly, then start removing fuses or connections to the positive battery post one-at-a-time until the offending electrical component is identified by the bulb dimming."
Here is the entire article if you want some lite reading
It's well written and respected throughout the RV community.