I bought a Magnecraft latching relay 755xbxcd-12c. Before I build my project, I wanted to test this relay. This is a DPDT two coil latching relay that works on 12vdc. My userstanding is that when I put 12 vdc on the set coil, the contacts move in one direction and when I put 12 vdc on the reset coil, the contacts move back. What actually happens is that the reset coil only moves the contacts temporarily when voltage is applied. What could be the problem?