Power to the poles of the OVP [7 pin] style first the harnes at the 30 pin is hot at all times, Pin 15 hot with key on. 30a ground, when ground is applied to this post and power applied to pole 15 the electro magnet pulls in to apply power to the 87# pins when testing the OVP on the bench you will have to use this guide to check propper function of OVP.