Here is another one on taking the switch apart.

https://www.oilburners.net/threads/fsv-tear-down.50770/

Charlie

 

I bypassed my fuel tank selector valve a long time ago due to it not working i had no symptoms other than it not switching tanks. After I bypassed the valve I unplugged it and took it out and my gauge didnt work I plugged it back in and my gauge worked again so maby a bad valve can cause your gauge to stop working.

 

Each sender has 2 wires that go into that plug. The FSS just switches the contacts inside it to
the proper tank.
As I remember replacing mine and rear tank couple years ago, there is 5 wires in the plug.
I wrote them down to where they went...there in my notes some where...


Charlie

 

A bad selector valve will many times report a fuel tank overfull on the gauge. If it is stuck in the middle it can cause fuel to be drawn out of one tank and return to the other tanks also. Another problem crops up when they get stuck also - it will supply some fuel but not enough to properly operate or start the engine and people will spend tons of time and $$$ trying to chase down problems when in reality it is the stuck valve causing the havok.

 

Bad fuel tank selector, olive, return line, fuel lines, shower heads, mechanical fuel pump....

all before the injector pump!

just knockemout.....bam....done...

soft line the hard lines.....
go electric fuel pump....

over
the end for what....150k

 

Just wondering, why would you have to cut the wires to the selector valve connector?
Thanks for the info, I have a 1988 F Superduty/450 cab and chassis, dual tanks, 460ci gas, 2wd.
I plan on deleting the rear tank because I can't find a replacement for the rear plastic one and the sending unit wire are broken off in the wiring harness connector plus I found a 100 gal aux. tank on marketplace for a reasonable cost and will be installing that instead.
-Joe

 

Not sure they were talking wires....maybe the actual fuel lines.

 

Ahh I see, they must be talking about cutting off the fuel like "quick connectors."
Thanks
-Joe