Hey New Rider,
I have had the same thing happen before, but not no more. I can wash my cart then get on it and go. I found out that if you spray down all connection ends in the battery compartment with battery post protectant (the red stuff from CarQuest) including wire harness ends, this will help your situation out greatly. That stuff also helped me out with battery wire end corrosion. I spray all ends down atleast 3 times a year after a good wash down.