A buddy on another site has this vehicle, but he is very discouraged at this point. He has registered here but i think is afraid of more run around. He states the po hacked his system up on the wiring and is looking for a factory correct diagram to go through his system to get it all functional. Does anyone have this image? If needed i can repost his posts to maybe give more info into whats going on for him. Hopefully he will chime in here. I told him you guys know and have access to most everything. Hope we can help him out.

 

This is what I got. the yellow and white wire goes to the gauge on the dash, red is power when key is on

 

Thanks David.

 

Here's another diagram of the same thing but showing a little more of the circuit.

 

Hello guys i finally made it in here thanks to the kindness of jazz Daddy. I see the schematic but my problem is two fold and maybe even better i better explain what a mess i have here.

In regaurd to the yellow and the white wire going to the dash fuel gauge is not correct for me because my tanks are wired like this Front tank has a black wire and a blue wire coming out of the top of the tank, the Rear tank has a red wire and a yellow wire so being that i don't have a white wire coming from the tank whichof the wires would take the place of the wwhite wire?.

I opriginally wanted to wire the tanks forweard because for one i have no dash mounted rocker switch and the toggle switch isn't hooked to any thing at all?. My front tan reads and rises and falls as i add and use fuel so the front tank is working but since i seem to have no fuel selecter switch i can never use the rear tank?.

I thing this brain damage i have experienced at the hands of the ford motor company has to end and i can't seem to find any one who can finish this night mare off by me getting the path way to re wire like David was trying to do its just that i don't know since i dont have a white wire David was speaking of what other wire would take the place of the white wire and is that the whole route for the wire on from each tank to the dash fuel gauge and the other red one from the rear tank goes to the power side of the ignition is that it?. it seems incomplete because the rear tank isn't in this direction?. Can any one say it starts at the tank and these wire go here and there?.

If no one has this pathway information on where the wirtes go then i have an alternate plan and that is since the front tank reads out on the dash gauge i figured i would eleimate the fuel selector valve on the drivers side frame rail and extend the fuel lines from the tanks to the cab and but a 1/4 inch 3 way manuel fuel selector valve and just use the dash guaage for the front tank and fill the back tank and figure 10 miles MPG up or down hill so my 20 gallon tank can go approx 200 miles at 10MPG and then switch the brass three way valve because at present i can not even selext the rear tank becaus ei can't determine if the toggle switch which is hooked up to nothing is stock or if there is supposed to be a factory rocker or toggle switch?. Pretty twilight zone if you ask me and i have been beating my head against the wall because opf ford motoer company.

Ford motor company was very happy they said to have me bring the truck in and they told me they could fuigure it out for me for a mere 6 to 8 hoursd at $120.00 per hour so for around $480.00 bucks thye could figure it out lol lol lol. I seem to be experiencing Americas best kept secret.

I have scoured the internet and found out that all this old information wa spurchased by companys to re sell on the internet so i am at this point SOl and that aint sole brothers lol.

If i can't find out how to rewire it i will just install the 1/4 inch three way brass fuel selection valve and guess at the rear tank , at least this way i can use the rear tank which at present i can not function the rear tank because i have no dash mounted switch save the toggle switch in the bottom of the right side of the steering colum and it of course isn't hooked up to any thing just hanging under the dash hooke dto nothing?. any help is apprieciated. I need to change my handle here to half ton crazy. I hate night mares in the day time. I am into this two weeks now banging my head on the wall for lack of info or even a place to get it. I hope ssome one here may help me understand the wireing path way so i can rewire .Thanks for any direction at all .

 

If the truck was factory equipped with dual tanks there should be a "factory" switch for it - even if the switch was abandoned at some point. So is there a factory switch (usually in the AC control panel, opposite side from the fan speed switch)?

Even if someone converted this tank to a dual set along the way, I would still try to get to work as a factory setup. Wire colors don't matter so much as does what the wire does, and where it connects to. The circuit is not very complicated. It won't be that hard to get it working right.

Also, sometimes aftermarket replacement parts will come with different colored wires.
Here is a link to a fuel tank switch. Do you have something like this? http://www.ebay.com/itm/1975-86-NOS-Ford-F150-F350-Fuel-Tank-Selector-Switch-/231307332300?_trksid=p2054897.l5662

 

Glad to see you made it Half.