Originally Posted by allure99
Thanks for your reply, my dash air doesn't work so it is never on, the vent might have been on sometimes but it is usually off. My high running temp is 180, but this dust storm happens even in the morning when leaving the campground, I fell bad for the people I dust and my coach gets dirty, my battery area is always covered in dust
The 180 operating temp suggests a problem with the fan controller or associated components. There is a coolant temp sensor, an air intake temp sensor, and a tericery (sp) switch for the A/C and vent controls. Any one of these sensors can turn the fan to high causing the storm.
First thing I would do is make sure you have 12 VDC to the controller. It should be mounted on the rear side of the radiator housing. A two piece square box with a couple of hydraulic hoses and an electrical connection is what you are looking for. Clean that electrical connection also. The ignition has to be on to see the 12VDC. Off hand, I don't remember which wires to check for voltage, look at your chassis schematic. From what I have heard, the hydraulic valve doesn't go bad but you might as well give it a couple of "love taps" with a hammer while the coach is running just to make sure it isn't stuck .
A new controller can be found for under 600 bux. If you have the part number, and order by part number, it will come programmed for your setup. Cummins Coach Care wants to charge for the "programming" which is already done. That part number will get you the complete assembly (controller& valve).
If you go to the CC Yahoo groups and look in the photo section, you will find pictures of the controller insides. I took the time to remove the potting material just to see what makes it tick. In the photos, you can see very clearly, some cold solder joints. Poor workmanship on the Sauer Danfoss side.