Project Spirit is a 1975 Maverick four door with an inline 250. She keeps killing her battery while running. Once you park her, you can't turn her back on because the battery is completely dead. We did a load test on the brand new alternator and it checks out fine as does the battery. we replaced the positive and the negative battery cables plus ground the wire to the new voltage regulator, and we checked the belt tension which was fine. We checked for any visible shorts and we can't find anything. There are no loose connections that we can see.. at this point, I'm utterly stumped. I can't find for any reason under the sun why she keeps draining her battery. Could it be a fuse or the solenoid acting up? Or is it something I'm over looking, maybe the starter? Any help is appreciated, thank you in advance.