When I put my little cheapo meter on OHM and then zero the gauge while putting both probes together. I then touch the combination of the prongs on the relay. The needle pegs all the way from left to right at 0.
The to confuse me even more, I take an identical used relay from the parts box and this one tests different, with the meter pegging over to right (0 again ) between two of the prongs, but not any prong and the case.