Gauge problems

[lester622]

I posted in the electrical part of the forum but no answers in there.

The fuel gauge in my truck reads a 1/4 off, as in empty is at 1/4 of a tank, i have no idea why. The previouse owner added a second tank and a toggle switch i have since removed the second tank but left the toggle switch since I havnt had time to search how its wired in since wires run from front to back on this thing. What would be a reason for the gauge to be off by a 1/4?

Also the water temp guage does not read correctly it moves but only goes up a small amount, the oil pressure guage comes on and pegs out but sometimes moves back down.

I changed clusters to make sure the guages werent off but with this cluster it still reads the same.

Im guessing maybe the senders are bad for the water temp and oil pressure but im not really sure, has this happened to anybody else?