you can try pulling the cluster and taking the clear faceplate off. then, carefully and gently push the gauge back. you shouldn't meet hardly any resistance.
I recently worked through gauge related issues, including an inoperative voltage gauge, also a dead oil pressure gauge and fuel gauge. I had my cluster rebuilt by RT Grim in Pennsylvania and had a pretty positive experience with them.
they replaced two meter movements, the microprocessor, connectors, and some other unspecified components.
if manually resetting doesn't work, that may be the answer. lots of 04-05 sport trac's clusters are going bad these days.
