This is on my 94 dually. I never use the front tank but the fuel gauge works in both. Today I switched it to the front the gauge went to where I think it should have been and the ac quit. I checked the fuses and it was blown. The ac is on the same circuit as the selector valve. I changed it and fixed the ac but now the gauge stays on the front tank instead of the rear where I want it. I'm guessing that the selector valve got stuck on the front tank and that is why the fuse blew. Does anybody here have experience on these dual tank systems? Anybody know anything about these valves on ebay.

http://cgi.ebay.com/ebaymotors/Ford-GMC-Chevy-Dodge-6-Port-Fuel-Tank-Selector-Valve-/110754203438?pt=Motors_Car_Truck_Parts_Accessories &hash=item19c977072e