how do you switch from one gas tank to the other on a 1982 f 250?
Should be a switch inside the vehicle to the right of the climate control unit which will say "Front/Rear" or something similar. However, the 1982 F-150 I had had a bad switching unit and so only one tank worked anyway. If you look along the frame rails between the fuel tanks there should be an electronic component there that allows you to switch. These are kind of known for going bad and I have seen numerous vehicles of this age with one fuel tank door pinned/welded shut, etc.
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