It sounds like you have an exciting project at hand with your 1988-1994 Chevrolet Silverado K3500! The error message warning about not driving in water seems like an intriguing puzzle to solve. Given that you've already fixed the rear bumper and attachers, the issue may be related to a water ingress sensor or wiring harness connection affected by moisture. I recommend inspecting the underside of the truck for any signs of water intrusion, including damaged wiring, rust, or any exposed electronics.
Regarding the optional features you mentioned, such as bumpers, mirrors, rack with LED pods, windows, plough and attacher options, and paint options, each of these customizations offers a great opportunity to personalize your Silverado K3500 according to your needs and style preferences. The versatility of these options can truly enhance the functionality and aesthetics of your truck.
When working on the truck's customization, be sure to check for any loose connections, worn components, or faulty sensors that may be triggering the warning message about water. Once you identify and address the root cause of this issue, you'll be able to enjoy your Silverado K3500 to its fullest potential.
Feel free to share updates on your progress or ask for further assistance if you encounter any challenges during the modification process. Good luck with your project, and I look forward to hearing more about your upgraded Silverado K3500!