The OEM tank selector switch in my 1984 F-150 never worked. I guess my dad bought the truck and had Ford install an after market auxiliary tank and selector switch mounted in a hole through the plastic dash near the hood release. When that switch fell apart in my hand, I did a little research, did not fully understand anything, and ended up using a DPDT that was in my electrical switch collection simply because it was heavy duty enough and had 6 connector tabs. To my super surprise it worked!
That lasted about four months. I have 3 wires, green, red and yellow from the fuel rail through the firewall. Inside by the fuse panel the yellow, is spliced to a yellow/white; a red, spliced to a red, a black spiced to a blue/white hash wire that has an in-line 20amp flat fuse and is plugged in from the front of the fuse box.
Now, being the genius that I would like to be, I ordered the switch that would replace the one in my 1969 F 250, simply because I could not find anything online but a rocker switch that would require me to enlarge the already huge hole in the bottom edge of my plastic dash and I was not going to attempt to take the instrument cluster apart. Now I have a problem with what wire color was supposed to work with the main tank's tie in, every electrical diagram from 1969, 1972 1976,1984 has different wire colors. I do not know how a switch works, and I am pretty sure this particular situation is only to switch the solenoid at the fuel rail for the aux tank on, giving me cause to disconnect the entire wire cluster at the new switch and see if the main tank would function as a single tank so I can tell if I am running out of gas. I have been topping off the front tank because it is the only one that will hold any gas telling me the truck is using that tank. That is how I found you guys, plenty of topics and questions, really easy to use the site, plus there was a section for pre 1987 trucks. Can anyone tell me if it is possible to wire the switch for the 69 truck to work in the '84 truck and what wire goes where?