I doubt you'll be able to rectify this - my '03 does the same thing, as far as I know it has done it since I first purchased it (used) 100K miles ago.
LibertyFever wrote:
I've read a service manual and it appears that if there's no access panel above the gas tank I'll have to drop the tank to gain access to the fuel sender unit to troubleshoot it. Do you suppose it's a bad ground at the sending unit?
There is an access opening above the sender unit/fuel pump but in order to get to it you'll need to drill out the rivets that hold the two tie-downs in place in the back corners of the cargo carpet, then you can lift the carpet and see the cover. In order to get the actual cover out you will need to take a hot-air gun to the sealing compound that covers the bolts and the joint between the cover and the bottom panel of the cargo area, then remove the bolts (10mm IIRC) and lift/pry the cover up. I did this when I was trying to reduce the noise that the fuel pump puts out in the HF/CB frequencies when I had my ham radio HF antenna mounted on the tailgate - I wound up drilling a hole in the front left fender and putting in a ball mount for my HF antenna.
In the long run it may just be easier and faster to drop the tank to see what is going on.