SnowDogg Part # 16151312 - HT300 SA Solenoid Drop Valve is used on generation 1 and generation 2 SnowDogg plows. The SA valve is located on your HPU on the hydraulic manifold assembly. If you're looking at the side of the manifold, the SA valve is the one at the end, closest to your relief valves. The SA valve is connected to the SA coil which has two wires connected to it's posts including the black cross over wire which goes to SB and the Blue wire. If you're having issues with your plow dropping or in float mode, this is a good place to start troubleshooting.