fuel gauge reads over full or below empty

[dirtbikes4fun02]

i have a '90 4 cyl 5-speed ranger standard cab long bed.
the fuel gauge when u turn the key on goes straight to full or straight to empty and it does it randomly. when u let it go to empty and cycle the key it will go to full, then fall off slowly when u turn the key off, then when u turn it back on, it will either go back to full or go straight to empty. and it has 1/2 tank of gas
i changed the whole pump, sending unit, float and everything last night. i checked all the wiring, and clean the plug wiring. i grounded out the yellow/white wire, checked the ohms on the sending unit, and everything checked out fine.
then i tried the gauge and still the same problems. could this be the slosh module?
i tried pulling the cluster out, but the speedo cable would not give me enough slack to unhook it and remove the cluster

somebody please help me out. i really need this to work.
thanks

 

[dirtbikes4fun02]

thanks guys!

 

[vader436]

did u solve ur problem, bcuz imhaving the same problem with my gauge, need help please

 

[Mark_88]

A bit late but...could be a bad grouund or a corroded connector on the top of the tank...mine has been wonky since I got the truck...when I had the bed off I cleaned the connectors and it worked better (though not perfectly)...a bit of dielectric grease in the connector goes a long way too...

if that doesn't help then you may need to replace the sending unit in the tank...