After enduring hurricane Frances and driving my '94 Explorer through some flooded areas about 12 inches deep my gas guage registered below empty the next morning after I started my truck. After filling the tank with gas the needle finally indicated a full tank after about 30 minutes of driving around town(25 miles). The next day and for the past few weeks it has shown about 1/8 tankfull (normal) when the key is off and immediatly goes to below empty when I start the truck. I have read many of the threads that speak about holes in the float, faulty sending units and corroded wires. Two days ago I located the connector behind the frame of the driver's side rear wheel and cleaned the contacts and applied some dielectric greese to the contacts. Before plugging the connector together I turned the ignition switch to KOEO and watched fuel guage register past FULL. This led me to believe the guage and wiring to the connector is OK to the connector. However, after I plugged the connector together I had the same symptoms as before (below empty when the truck was started). Yesterday when I was driving during a huge rain storm the guage crept up to a full tank (I had just filled the tank that morning and only driven about 20 miles) After about another 20 miles the guage returned to below empty. This led me to believe I didn't have a hole in the sending unit float. Do you all think the sending unit has problems or possibly bad or corroded grounding of the sending unit? Also where do I check the connections for the ground and where are the connections for the sending unit? Any help would be greatly appreciated.

 

Since the gauge needle is moving, that suggests that there is something registering from the sending unit. In my experience working with electronic components, it sounds to me like there may be a faulty ground. The changing behavior when wet also supports the faulty ground possibility.

 

Full reading with plug-in to pump assembly disconnected is correct. You no doubt have the infamous float failure. Part is around $5.00 at Ford, but labor to install is another story. You must drop the tank and remove float/ fuel pump assembly to replace.
Dialtone

 

Thanks for the replies. I had another rainy day and the fuek guage went up to about half a tank after driving on wet roads for 20 minutes. I had traveled about 150 miles since my last fillup, so I don't think I have a hole in the sending unit float. Today was a sunny day and the guage was back at empty. I'm thinking that I have a bad ground from the sending unit or a poor connection somewhere past the connector at the rear wheel. Does anyone know where the sending unit is grounded or where else I might check? Thanks in advance.