WINDSHIELD WIPERS NOT WORKING

We did download the diagrams from the Winnebago website but it did not identify the IPX master controller location. When we were at Winnebago and they were trouble shooting trying to identify the problem, They also printed a couple of diagrams but still could not locate the IPX master controller. They found that the fuses were good, there was no ground problem and changed the smart wheel module on the steering wheel but the wipers still did not work, Winnebago told us to go to Freight-liner since they were the manufactures of the chassis and would know where the IPX master controller was located. While we were at Freight liner they spent quite a bit of time on the phone with the help desk but to no avail no one knows where the IPX master controller is located. Pretty sad when you think that Freight-liner manufactured the Chassis and they don't know where the IPX master controller is located, doesn't give us confidence in them..