Hi folks. Very new to this whole deal, so I apologize if I do something wrong here. What my problem is: I am working on a 2002 F-350 7.3 Powerstroke that had the fuel tank start on fire. I was called to tow it in and fix it. All repairs are done, but there is 2 things I do not know. First: is it correct that the front and rear tank vents both hook up to the steel pipe in the frame rail? I know the back one does because it was still on but the front was burnt off. If this is the case, does anyone know why they do this? (I am just curious), and can a guy just run a piece of hose from the front to the back and achieve the same result? Second: The new fuel level sender has a pink and a yellow wire coming out of it. The factory plug and part of the harness is melted away, and not available apparently, so I am going to just eliminate the plug and wire it direct. The problem is the factory harness has 4 wires and I do not know which two I use, and which way the get hooked up. I have 3 different wiring diagrams, and all give different info. I hooked it up the way I thought is goes, but the gauge does not work. Does anyone have any knowledge of this, or have a dump truck that they can see the top of the tank without a bunch of effort? I really appreciate any help.

 

The pink wire MAY be a resistance wire.
Find out, before you do any damage.

 

The vent hose from the front and rear are connected through by a rigid line along the frame. The front also has a vent on it that you can see in the picture below. This simply allows each side of the tank to vent out the same point. In addition, there is the vent hose near the fill neck port.



I cannot help with the wiring, but when I removed my sending unit I snapped this picture, it may help you a bit.

 

Thanks to ligito and Saus for their replies. I did take note of the wiring on the sender before I put it in the tank and noticed the pink wire is screwed to the steel piece inside. This makes me assume the pink is ground, However, I know, or at least I think I know, that these things are not just 12 VDC and ground, but that the voltage or frequency or something of this nature changes with the float location. I am not sure on the specifics, obviously. Thank you for clearing up the vent question. I just ran a hose from front to back, but I suppose I should put a vent in there as well. Is there any way to test to see if the wiring and gauge itself is functioning to make sure that there is not a different problem? Thanks again.

 

UPDATE: Thanks to Sous, I finished the vent tube thing, got the part off of a totaled out truck. While I was there, I looked at the wiring and found what I needed. If anyone cares, the yellow from the truck goes to the yellow on the sender, and the black/orange from the truck goes to the pink on the sender. The pink and black from the truck are not used. From what I can tell, using the schematics I did get my hands on, the pink is fuel pump power and the black is fuel pump ground, so I assume they use the same harness for gasoline trucks. The strange thing is, I had it hooked up right the first time, but it did not seem to work, so after I knew for sure, I was going to hook it back up, and assume the new sender was bad, or there was another issue, but my work was as done as I could do it. Anyway, when I hooked it back up, the gauge works now!! Go figure. Thanks to those who helped for helping and thanks to everyone else for previous posts that we are allowed to see and help everyone out. I have a poor opinion on forums from the past because so many people whine and complain if you ask something that has already been asked. While I understand the point and agree that you should look around before you ask, I also feel it is easy to ignore the person if it bothers you that much, or just send them in the right direction. Anyway, thanks for everything, and have a good spring.