fuel guage pin stuck below E

Hi, I am not sure how it happened but yesterday I changed the spark plugs in the car. I changed the oil. Other than that, I didn't do anything to the car. I disconnected the battery for a little bit. Now, for some reason, when the car is turned off, the pin points straght down. When the car starts up, the pin goes up to the point where the guage pin would normally rest on when the car is off (about where E is at). That pin pointing out stops the gas guage pin from going any higher. So basically the pin is stuck below E.
Now to change the back spark plugs, we did remove the altenator. I am reading on the internet that someone else had the same problem with a Malibu when changing the alternator. We disconnected the bolts to make it easier to get to the back spark plugs and we undid the electrical plug that goes to the altenator. (Maybe that will shed some light on the problem.) Does anyone know why this happened and how to fix it.

Disconnecting the battery did it...

This is an air core type movement, so when you remove power with the needle in the wrong position, it will sometimes do this.

Best thing to do is remove the cluster and rotate it around until the needle is on the other side of the E peg.