I am looking for a 12v polarity reversing relay that switches the hot AND ground by energizing 1 signal wire. The relays I located so far will switch the hot but not the ground at the same time. The 12v actuators I am using have a 2-wire lead that controls the permanent magnet motor in the actuator. The actuator has built in limit switches at each end of stroke. The direction of travel is determined by the polarity of the 2-wire input lead. The actuator will be used to stop and start a mechanical clutch on a drive system (agricultural equipment). The actuator will be automated thru a on board GPS (Trimble) system. The only power source available from the control console is a simple 12v off/on power supply. If the 12v off/on power supply could be used as a signal wire to a polarity reversing relay, I think the system will work. The relay will need 2 inputs (hot & ground); 2 outputs(hot& ground) and 1 signal wire ( to switch polarity between incoming and out going current) and maybe 1 case ground. Is a relay of this sort availible????