F-250 tank select switch/fuel gauge malfunction
David Schwarz
07-03-2005, 12:08 PM
1992 F-250 with 7.5L V8. The fuel gauge for the front tank registers empty, even though there is fuel. I know the problem is electrical in nature because the gauge started working when the switch broke free of the instrument cluster cover (I left it dangling inside for a few weeks). After supergluing the switch back in place, the gauge no longer works (and yes, I tried letting it dangle again, and that didn't "reintroduce" the fix). I've checked the integrity of the connections and they appear fine. A new switch didn't solve the problem either. What I really need is a good wiring diagram for the switch that improves upon what I can get in Haynes/Chilton. There has to be a wire that I can trace to solve the problem.
badasstour
10-13-2005, 03:13 PM
just follow the wires and look for a break in the wire or a weak spot
David Schwarz
10-13-2005, 11:30 PM
This is so old I had forgotten about it. But since I'm here, I figured I'd share the solution. It turns out that the float had a hairline fracture in it. When the switch had broken through the panel, it was because my friend had drained the tank, and was switching to the other tank. I figure what happened was once the tank was empty, the float was able to drain; it then worked for a short time until the float filled with fuel again.
The fix was simple - drop the tank and replace the float. There were two hurdles I encountered along the way. First, the cheap plastic fuel disconnects you can buy from Kragen are crap - I guess you get what you pay for (I now have a cast aluminum tool that will handle all my future fuel line disconnect needs). Second, raising and lowering the tank is a handful when you're tackling it alone (particularly the raising part). Picture lying on your back curbside, tank precariously balanced on a car jack with one hand, while the other hand attempts to pump the jack...
This is a good job for a friend and a 6-pack :)
BTW - I did end up buying a factory wiring diagram - that's how I determined there wasn't a wiring problem.
The fix was simple - drop the tank and replace the float. There were two hurdles I encountered along the way. First, the cheap plastic fuel disconnects you can buy from Kragen are crap - I guess you get what you pay for (I now have a cast aluminum tool that will handle all my future fuel line disconnect needs). Second, raising and lowering the tank is a handful when you're tackling it alone (particularly the raising part). Picture lying on your back curbside, tank precariously balanced on a car jack with one hand, while the other hand attempts to pump the jack...
This is a good job for a friend and a 6-pack :)
BTW - I did end up buying a factory wiring diagram - that's how I determined there wasn't a wiring problem.
badasstour
10-14-2005, 01:08 AM
ok sounds good just thought id puy in my two cents
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