I think there is a pin three marks to the left of the needle should rest against. On the FULL side, I only have seen the needle run to the third mark past the FULL mark. I don't think there is a pin for the needle to rest against. I believe the needle relies on the internal mechanism, what's on the other side of the faceplate, to prevent it from going to the bottom.
It seems the needle has come detached from the meter movement, as in the spring broke. I don't thnk there is a fix, at least overnight for this.
Others here may have a solution....
Everett "OBJECTS IN THE MIRROR APPEAR QUICKLY UPON RAPID DECELERATION"