Behind the right rear panel is two modules. One is closer to the front of the truck and controls the rear heat. The other module is closer to the rear door and controls the rear a/c and the heat. With this being broken, the air from the roof is coming out hot with the a/c on. So, I removed the module. This stopped the clicking noise but it still blowing hot. Also, who knows what the cost of that control valve is. The tip is broken and I am going to try to glue it and see how long it lasts...

The actuator which is behind a panel over the right rear wheel well starts clicking when vehicle is started and then continues till it damn well pleases. I haven't noticed any effects to the vehicle operation other than I hate driving it with all that clicking.