Well, if misery loves company then we are in the same boat.
I have had exactly the same thing for about 3 months now. I have not taken the time to remove the cluster, but I think the problem is there or a wire.
As I understand it, when the circuit is closed and grounded, it reads 3. When the circuit is open, it reads 0. If you figure it out for sure, I would really appreciate knowing. I have nightmares about going to pick it up after someone spent 8.5 hours tracing a short.