Full tank = gauge reads empty

[Switch_knuckles]

Ok When I got the Nasty (95 Cherokee) the fuel pump went out. I replaced it with one from the j/y. All was good with one exception. When the tank is full the gauge reads empty. I hooked everything up exactly how it was before I removed the pump. Today I replaced the pump, strainer, gasket, lock ring and even replaced the fuel filter. The fuel system works GREAT. Just one problem,... the gauge still reads empty when it is full. Any ideas?

[bluedragon436]

Sounds like your fuel level sending unit is shot... I know usually the contacts get corroded when the tank isn't filled for long periods of time, or people continue to keep it below half a tank to save a few bucks when they get gas... like mine will randomly read empty when it isn't, but then it will go back up... but it sounds as if yours is either completely shot, or maybe the float has gotten caught up or the arm has been bent over time from being installed incorrectly!!

[4.3LXJ]

Yes, most likely sending unit. You can test the gauge by grounding the wire to the sending unit. Gauge should read full

[jccatt]

Mine does a similar thing. If i fill it it reads empty a lot until its below half then it works normal. Sender munted was my guess.

[prerunner1982]

Ok When I got the Nasty (95 Cherokee) the fuel pump went out. I replaced it with one from the j/y. All was good with one exception. When the tank is full the gauge reads empty. I hooked everything up exactly how it was before I removed the pump. Today I replaced the pump, strainer, gasket, lock ring and even replaced the fuel filter. The fuel system works GREAT. Just one problem,... the gauge still reads empty when it is full. Any ideas?

Does it ever read something other than empty?

Could be the gauge...

[Tural]

the gauge that came on my blue one did that... you know, the one in a dummy cluster... i put a full cluster in and it's working correctly now...

[Switch_knuckles]

It reads backwards! Full when empty and empty when full. I will try the level sending unit. Thanks guys.

[Mudderoy]

It reads backwards! Full when empty and empty when full. I will try the level sending unit. Thanks guys.

What a great anti theft device! Just just have to keep the tank full, ahhh, empty.... :out:

[LizardRunner]

A gauge reading backwards might mean the wires are connected backwards. Just a thought.

[Switch_knuckles]

A gauge reading backwards might mean the wires are connected backwards. Just a thought.

I thought about this, but I hooked everything up as it was originally. And all the connectors are size oriented. (i.e. the little connector won't fit on the larger connection)

[uberxj92]

my 90 does the backwards thing too. my 92 only reads to the 3/4 mark LOL

[4.3LXJ]

A gauge reading backwards might mean the wires are connected backwards. Just a thought.

I understand your reasoning. But if the wires were hooked up backwards in the dash, which you cannot do, it would short out the printed circuit in the back of the cluster. On the sender end, there is only one wire, the ground wire that grounds itself through the rheostat in the tank.

[ralphy]

just a thought, did the j/y pump come as a whole assembly (pump & float) and if so was it the same year model? that might make differance.

[Weldmen]

Sounds like it might be mounted upside down. The float should be twards the back of the tank.

[Switch_knuckles]

just a thought, did the j/y pump come as a whole assembly (pump & float) and if so was it the same year model? that might make differance.

This is what I was thinking, the pump and float came from a earlier model. A 93, I believe. Mine is a 95.