A bad Fuel Sender??

[mjs2011]

So yesterday, I hopped in my truck, noticed my fuel level was low, and that my other tank was supposedly plum full, so I switch over, and the fuel level needle immediately dropped off as low as it could go. I switched back to the other tank and started wondering what the hell was going on. I was certain that the tank was full, and I hadn't even used it since I last filled up. I headed to the station and started filling, and only got one gallon in the front tank. So it was full, but the guage still shows that its completely empty.

So now my question. Is it just the sender that is bad, or is the tank selector valve malfunctioning alltogether? And regardless, how can I fix it?

Some other possibly useful info. It is the front tank that reads empty. We also just got a bout of snow here in SD, and Ive been driving through alot of snow and slush. Not sure if this would make a difference or not.

 

[OLDBULL8]

You could check at the FSV for a broken wire on the connection, it's the center wire on the connection that goes to the front tank. or measure with an Ohm meter from ground to tank sender, no reading would be an open circuit to ground thru the tank variable resistor, a 000.00 or a little more reading might indicate the float has a leak in it and sunk to the bottom. If you get an ~80 ohm or more reading, then the circuit to switch is defective.