I put a new battery on my 2003Explorer today. Now the fuel gauge is on empty and will not move. I know the tank is full. Anyone have any idea hwo to fix this?

 

Not sure what the fix is, but you might try disconnecting the battery for ½ hour to let all the computers reset. I know that my 2003 will sometimes only show half or three quarters full after a fill up. It may only last for a little while, or for a day or so. It appears to be something in the electronics, as it always either comes up real slowly, or after the car is cut off and started back up later. Acts like something is wierd with the signal filter circuitry or something. Anyway, that's why I think it's possible that a reset of the systems could fix your issue.

 

Thanks. I will try it today and let you know if it works.

 

If it's not gauge related, try banging on the fuel tank. Could be a stuck sending unit, although that should have any impact with replacing the battery? Were you having any electrical problems prior to replacing the battery?

 

I left the battery unhooked about 4 hrs. Hooked it back up-no luck. After 45 minutes of driving the needle slowly got up to 3/4 full. Then it fell back to empty. We went shopping for about a hour. When I cranked up the gauge started working correctly.. I don't know what caused it to fail or why it started workiing. Just glad it did.

 

I'm glad to hear it started working for you. Sound's very similar to how my 2003 behaves sometimes. I haven't found out what causes it yet. It has fixed itself so far, so I haven't been able to do much analysis. But because it fixes itself, I suspect something in the electronics, particularly in the signal filter logic that keeps the gauge from bouncing excessively when the gas is sloshing in the tank from vehicular movement.

 

My 2004 Explorer fuel gauge sometimes doesn't go up to full after filling. There is a TSB that says you should use Techron to clear up fuel sender problems.
The best explanation I have heard is that anti-slosh programing prevents the fuel gauge from reading erronously if it detects a recent drastic change in fuel levels caused by off-roading. It is programmed to read correctly in about 45 minutes of driving. I am not sure why it only happens some times.
Just another Ford quirk.
I recently replaced by battery and didn't have a problem, but it might depend on how long the battery was out of hte vehicle.

"If Ford had a better idea, why didn't they use it?"