OK this one seems really strange. I just picked up a '99 SD 7.3L. Tested the operation of everything before buying it - all was OK. Including the wipers. Used the wipers once or twice since I got it - still OK. Today, fired it up and hit the wipers - engine immediately shut down. No stumbling or missing - just a total shut down. I restarted and repeated this four or five times, shutdown every time. Rain quit so I drove to where I was going, hit the wipers when I got there after a thirty minute drive - instant shutdown. Drove back home, same thing. So I pulled the wiper fuse (#11) and tried every position of the wiper stalk - no effect, engine kept running. Put the fuse back in and tried the wipers - all is fine, engine kept running. So now I have a potentially dangerous problem that could reappear anytime I use the wipers, and no idea what is causing it. Anyone have suggestions?