ESR meter construction question

I finally built my ESR meter kit from John and it "works" (it powers up, displays "EA" and then "- ") but when the measurement leads are tied together in order to zero them out the value just keeps fluctuating wildly. The fluctuation is large and happens a few times a second. If I press the button to zero them out it turns the meter off. I'm doing this with the ends of the wires off the PCB (the PCB has not been installed in the case yet) clamped together. Any ideas?