fuel guage issues

[bbever]

Hello to Everyone,

I have a 2000 gmc K3500 5.7L with dual tanks seem I have become victim to gmc's fuel guage issues saw some of the threads and thought I could get some valuable info in trouble shooting problems I'm having. Have talked with some mechanic's both they don't seem to have much experience or resources concerning this area on these trucks. Hope I can resolve my dilemma.

thanks, bbever

 

[MrMarty51]

Hello BB, welcome to thetruckstop.
What kind of problems are You having with Your fuel tanks ?

 

[bbever]

Not sure I am getting correct ohm readings from sending units front is 40-250 and rear is 0-90 ohms thinking front pump sending unit is wrong one

 

[MrMarty51]

Could also be a corroded connection in a wire. Giving a higher reading of resistance.

 

[MrMarty51]

But then again, I aint too smart on this electrical stuff so might have to wait for someone else that is.

 

[bbever]

sorry i'm slow responding figuring out how to get around on this site never done one of these before lol.. I did take the readings right off the sending units not sure if that will give me inaccurate reading or not but one guy told me that both su's should be 0-90 ohms but I got a new pump and sending unit and its reading same as the old ones.

 

[ak diesel driver]

Have you read this one?

Diagnosing dual tank balance module

Anyone with dual tanks having problems with fuel gauge or the automated balance flow system this may help. This module is located by the front (main) lift pump. Slightly toward the rear of vehicle along the frame rail. On top of this module is a fuel pump balance relay, it turns the rear...

www.thetruckstop.us

 

[Stoney]

Welcome to TTS.. glad you joined..

 

[THEFERMANATOR]

All diesel sending units are 0-90 ohms(actually 1-95), but ALL gas units changed to 40-250 ohms starting in 98+(V6's changed in 97). Sounds like somebody put a diesel sender in your rear tank instead of a gas sender. Also keep in mind 98-02 obs truck gas fuel gauges are run through the PCM, and all obs dual tank trucks use a dual tank balance module to control the transfer pump, and convert 2 senders in to 1 gauge signal. I posted diagrams and service manual scren shots a few years back trying to help somebody else get there 98 dual tank gas gauge working.