Fuel gauge switch wiring

[flynylon]

My situation was this: The second to last PO had stopped using the rear tank because "there was something wrong with the gauge switch." The AUX seemed to work, albeit pretty inaccurately, but the MAIN would peg to FULL when you switched it over. So after I got a great deal on a new one from Jason at BCB, I put a new sending unit in the rear tank. That also gave me a chance to see what condition the tank was in inside. Still, I got pegged when selected to MAIN once it was all hooked up.

I also have a manual fuel tank selector.

So I pulled the switch to check the wiring and here's what I found: Holding the toggle pointed at me, top of the switch facing up, I had the yellow/white wire on the left terminal, orange with the blue terminal in the center, orange with the red terminal on the lower right, and on the top right there was a red wire with a black terminal cover that ran directly to the ignition switch.

I pulled the red wire off and replaced it with the orange/red term wire on the top right terminal. Now the gauge works for AUX and MAIN!

Question is, what the hell is the red wire for? And why would somebody hook it up to the fuel gauge switch? Is that a remnant of an electric fuel tank selector wired incorrectly?

 

[fablife]

see if this helps a little, JD
http://deepsoutheb.com/tech//FUELSWITCH.JPG

 

[oleguy74]

they did not come with electric valves.leave red wire off.the red is part of stock wireing.that wire you say is red really goes to orange from main tank orange.someone disc the wrong wire and you put it back right.not sure where it goes.i will pull mine apart tomarrow and let you know.i think it is a bypass when they had only a main tank.there is also a blue wire in the harness tha goes to red when main tank only option was used.

 

[flynylon]

Stock wiring

That's a lot of the problem that I kept running into. Any schematic I could find was either a setup for the electronic fuel switch or it was somewhat deceptive in the OE drawings as they show a layout that does not correspond to the actual layout of the posts.

From what I have gathered, and for future stock setup questions, if you pull the switch from the dash and hold the toggle in your fingertips with the toggle pointing at you and the flat on the threads is facing up, you should see the yellow/white wire (to Aux tank sending unit) on the top left post, the orange wire with the blue female terminal cover (to the instrument cluster) on the top center post, and the orange wire with the red female terminal cover (to main tank sending unit) on the top right post. All other posts (the lower three) should be empty.

So what say you? Is this correct for a stock setup?

I really like the stock setup with the manual tank selector because if you switch it to the vertical position, you've got a very effective lo-jack system, as the thieves ain't gettin' very far with no gas unless they know where the manual switch is. After that, if you notice the empty gun rack between the seats, you should start worrying how much ground I have covered since you swiped my baby. http://classicbroncos.com/forums/images/icons/wink.gif

 

[oleguy74]

that is correct wireing.

 

[flynylon]

Thanks, Oleguy! That's what I thought!