It shouln't be that big a deal. Most valves are built for industrial abuse, so a little water shouldnt hurt anything. I've done several setup, my own included, with valves under the truck with no problems. Go back through and check on your wiring, make sure you dont have any issues there. Also, it is possible that you've got some debris in the valve....dirt, stray piece of teflon tape..whatever..causing it to stick..
Bagged '85 S-10 Blazer
Need bags, fillers, roll pans or custom LED kits?