I have read most of these posts and everyone is dead on. I don't see any info on what is called a vibrator. In some older vehicles a vibrator (usualy located on the back of the instrument cluster)is used. This little sucker can cause all the afore mentioned problems. Pulsing guages,inopperative guages and incorrect readings. Were they used on these old bolts?
The fuel guage system like the electric fuel pump has me wondering. You see electricity and gasoline don't mix. Why do they not explode? I mean realy an electrical appratus emersed in fuel, some people call this a bomb. But I have never heard of a vehicle explodeing from an electrical failure of a sending unit or an intank fuel pump.