ford escort zx2 alternator / voltage regulator / charge gremlin?

[John]

so i have 02 escort zx2 was driving and battery light came on so went home and checked to find that the ground on the alternator had melted the plastic around it and fused to the alternator. so figuring that voltage regulator had gone i went out and bought a new alternator w/ voltage regulator built in. cleaned up the ground and replaced the battery and alternator. had them tested only to find out that the alternator was still pumping out about 17 -19 v when rpm is above 2000 causing all electrical systems to speed up and brighten ex headlamps, windshield wipers, break lights, dash. soon after that i noticed that the battery was boiling over and the alternator was incredible hot after only running for a few minutes. so if anyone has any ideas i would appericate them. i'm leaning towards a short and if so would need advice on how to correct this.