Ok I have a 1979 F150 Custom 4x4 long bed. It has 2 tanks but the side tank does not look like the one's on LMC or Broncograveyard. It had a flatbed when I bought it so I took it off and sold it cause I would rather have a regular bed. The guy that had it before me did some plumbing and put in his own fuel tank selector down below the seat. So how do you know if it was a one or 2 tank truck?

 

Is there a switch on the right side of the heat-A/C control panel to switch the tanks?
On factory dual tanks, the tanks are switched electrically. The switch also changes the fuel gauge.
If you have a manual valve then the tanks are aftermarket.
Here's a picture of the right side of the panel minus the switch.

BTW, welcome to FTE. Lots of good people here.

 

Ok mine does not have that switch. There is a little toggle switch below the headlight that says Travel Tanks- Aux&Main. That switch works as far as I can tell. The side tank is the only one I can use right now as the rear one has issues,but when the switch is up it shows I have fuel in front tank as it should but push it down and the needle moves down towards empty like it should I would post pic's but I don't see how too.

 

BTW my pic is the truck I'm working on.

 

Okay, you have an aftermarket auxiliary tank not the factory dual tanks.

 

Mike, mine used to have a rear tank, it has 2 fuel doors, and some of the plumbing, does that still mean it is aftermarket? I passed smog cuz it was overlooked, but i need to install a rear tank and all the crap to ensure next years smog....even though i cant afford to fill it anyway.

I saw an AC switch with main/aux switch in a boneyard, maybe shoulda grabbed it...

 

I would say your truck came from the factory with a single rear tank (called the "aft-axle tank") and the mid-ship tank was added by a previous owner.
That's actually quite common. Sometimes two additional tanks are added, one on each side.

 

How do you post pic's on here?

 

Here's one way to post pictures, another is, if you're a paid supporter, you can post pictures as an attachment. To me, that's the easiest way. Two clicks and your done.
https://www.ford-trucks.com/forums/1...l#post13584225

 

Thanks Mike I will see what I can do with the pic's.