This is a long a twisted tale. Hopefully not too confusing. I have a 91 Laredo. My fuel gauge stopped working a while back. I thought I figured out that the problem was the fuel sending unit, so I replaced it. Then I was having an issue where my needle wouldn't go all the way to the F with a full tank and it would hit E after only about 11 gallons. I have the 20 gallon tank, so this confused me. I tried replacing the fuel gauge with an aftermarket gauge and in doing this I had to remove the fuel gauge from the cluster because it was dragging down the current on the aftermarket gauge and making it not read correctly. The aftermarket gauge worked ok but it bobbed up and down a lot. I did a bit more research and found there are 2 tanks that came in these. I drained and filled my tank again to be sure it was the 20 gallon tank. Thinking I may have purchased the sending unit for the smaller tank, I purchased a new one specified for the 20 gallon tank and replaced the original fuel gauge back into the cluster. Now finally to my current problem. When the ignition is on the gauge goes all the way to F and beyond and the idiot light comes on at the same time. Did I screw up the original gauge by removing and replacing it?