Ground to gas tank?

[Jrgunn5150]

Is that a thing?

My 91 cluster in my 79, fuel gauge reads past full, 3 o'clock, at all times. Cleaned ground, ran it straight to the battery, no changes either way.

This is a new 87 sender in a new 87 tank. Idk where else to look without dropping the tank back down.

 

[Vbb199]

May wanna consider checking resistance on the range of the sender's float.

Resistance on the sender is 0 ohms = empty
90 ohms (or so) = full

Unfortunately in order to check that, you'll have to drop the tank.

OR

The fuel instrument on the cluster could be defunct.
Obviously you need 12v+ and 12v- feeding to the gauge to energize the coils
(there's a coil on the empty side, coil on the "full" side of the gauge)


(if I recall correctly, if you grounded the fuel gauge sender wire to the body, it'll peg all the way to..... Empty? Where as putting the sender wire over to the battery positive terminal pegs it to full.

On a 91 insutement panel, I believe the fuel level sending wire is purple, small.... 6-8 gauge? Purple wire.

All that mumbo jumbo translates to = check to see if the gauge is energized.

An easy way to tell if the gauge is energized is by turning the key to "on"
And flicking (for lack of a better word) the needle, if it's energized, it'll point right back to where it was.

If you can point it to whereever you want.... You got no juice to it!


Edit: I may be wrong on the resistance numbers, but I'll search here directly in my notes


Edit again: 0-95 ohms

 

[C10MixMaster]

Is that a thing?

My 91 cluster in my 79, fuel gauge reads past full, 3 o'clock, at all times. Cleaned ground, ran it straight to the battery, no changes either way.

This is a new 87 sender in a new 87 tank. Idk where else to look without dropping the tank back down.

the easiest way to eliminate the gauge is to ground the sender wire it should go to empty/ unplugged should go to past full.

ohmm readings are 0 full , 88 empty.

new sending unit did you possibly connect to the fuel pump wire? and not the sender wire?

Not sure i completely understood the initial question but yes there is a ground to the sending unit.