I have a 83 300sd that everything on it it worked until yesterday.I switched from heat to A/c and nothing.Nothing to do withthe heat or a/c is working now.Both 11 and 10 fuses are fine but nothing works no fan,no a/c clutch the only thing that seems to work is the water valve.When you push the buttons on the controller you can hear the valve opening and closing.About 6 months ago it did blow the 10 fuse but since I replaced it has worked fine until now.Does it have any kind of relay for this?