Hello I have a 2004 dodge ram 3500 heavy duty 4x4. It is a diesel with a manual transmission. The engine is a cummins 24 valve turbo deisel with 135144 miles on It. The problem I have is when it rains the wiper delay does not work and sometimes none of the wiper selections work. But I only have this problem when it rains. They work any other time. So if you can, please tell me what the problem might be.