Working on the Furd
Thread Starter
Retired Senior Admin
Expert Gearhead
Joined: May 2006
Posts: 29,661
Likes: 43
From: Sheboygan Wisconsin
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.
Thread Starter
Retired Senior Admin
Expert Gearhead
Joined: May 2006
Posts: 29,661
Likes: 43
From: Sheboygan Wisconsin
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.
Senior Member
True Car Nut
Joined: Mar 2010
Posts: 7,124
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From: Portage mi
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
Thread Starter
Retired Senior Admin
Expert Gearhead
Joined: May 2006
Posts: 29,661
Likes: 43
From: Sheboygan Wisconsin
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.