First the truck: 91 V3500 3+3 w/ tbi 350 (bone stock, 150k, normally runs fine) The problem: 2 times now the engine has shut off while driving like the key was turned off and 2 times the truck will only turn over but not crank and run. Every time switching the dual tank switch from side to side seems to correct the problem and the truck starts and runs perfect. There has been plenty of gas in the tank each time and the guage seems accurate My question: are the fuel pumps wired through the dual tank switch on the dash? I'm wondering if the dual tank switch is dying and causing the problem. /forums/images/graemlins/thinking.gif TIA!