This truck is driving me nuts. I gave up with fixing the tank. Ordered a new tank, will have it next week. The fuel pumps are getting on my nerves. Without a manual it'* a slow process of asking on the F150 forum and figuring it out. So far, I have voltage threw the fusalbe link, that goes to the fuel pump relay. The relay seems to switch with the key and I pass battery voltage threw. I tested the inertia switch, it'* good, if not the relay wouldn't work. So far it seems everything works except what'* between the relay and the fuel pump. There'* a switch to choose the tank. I'm starting to think that'* it. Just need more time to test it. Fix one problem at a time.

Your problem is its a ford lol..Seriously i hope you can get it all figured out and working properly

I'm sure I will. I can fix a GM, but Ford is a bit of a unknown right now.

The tank selector switch is probably the demon Dan. Fought this with a buddy and his truck a few years ago.

I'm getting conflicting information from the F150 forum. One guy is telling me I need battery voltage going threw the inertia switch. I have 3.6v. That'* the voltage I would expect for closing a relay.

Yeah i agree with you dan see its not that i hate fords just dont care to work on them is my thing...But my buddy also had the same issue on his 94? and it turned out to be that switch as well as my step dads 88

Dan did you bypass the inertia switch and then try?

I have not bypassed it. But I tested the inertia switch and it seems to be working.

Well, after days of messing with the fuel system, and getting more and more confused. I keep getting advice stating different wire colors. I finally got hooked up with the guru. I posted up pictures of what I have and he says, that'* a 1991 relay and socket, and that explains why nothing seems right. He posted up a 1991 diagram and guess what, it all makes sense. Looks like I have only .04 volts going threw the relay. Looks like a bad fuel pump relay. Just great, all this over a stupid relay.

Ouch well at least it somewhat simple now..Still sucks when you go through all that for something stupid