Where is the dual tank fuel switch on a 86 ford f150?

The fuel selector switch on an 86 Ford F-150 with dual tanks is typically located in the cab, near the lower dash area, usually to the left of the steering column. It might be integrated into a panel with other switches, or it could be a stand-alone switch. It's often not immediately obvious and may require some searching. Check carefully around the area indicated. If it's not there, check the owner's manual (if you have it) which might provide a diagram of the switch locations.