Battery Drain

[Dads502]

I have a recently restored 69 Camaro with Painless wiring, and Optima battery mounted in the trunk. It has a high output Alternator, and 1 gauge cables running from the trunk to the engine. While driving, the battery charges normal, but after shutting down the engine, there is a 4 amp draw on the battery as measured with an ampmeter on the cables. I have checked all fuses and nothing seems to be related to the current draw. It will go away after several hours of sitting, and it will also go away immediately if I disconnect the battery cable for about 10 sec. Does this sound like a bad relay, or battery?