Cyberdyne fuel guage and stock guage ..help me!!!

[cantbuytime]

Ok my gas gauge stopped working other day, so i put in a cyberdyne gas gauge...... When i did that my factory gauge started working again... They both worked fine last night then today i turned on the key and the digital guage did a countdown to 1 and stayed there and when i cranked the truck the digital just reads full... Then on my way home from the store this morn my factory guage stopped working..... AGAin!!!!!!!!!! i have the cyberdyne WIRED - red wire To 12v Ignition, purple wire to panel lps switch, black to ground and white wire to Tan & white wire from fuel pump for signal... this is under the hood where I have it spliced in.... is that the right wire from the tank???? it is also coupled with a black wire in the loom, and looks like the is a plug connector on the fire wall.. Please help

[cantbuytime]

also when my stock guage stops working it goes to a 1/4 of a tank

[z07]

With the sending unit out of the truck you should be able to see the resistance change smoothly as you move the float from empty to full. If the sending unit isn't changing resistance over the full travel of the armature over the windings then there is probably an open or short in the windings. Before you go into the tank, you could also just spray out the connectors with electrical parts contact cleaner.

[cantbuytime]

Its a 1988 chevy 1500.. if it helps

[bradrhale]

im with z07 on this. check connections or possible broken wires.