Need Help - with fuel sending unit

[Dan Acosta]

03 6.0 YXL 2500 - It is a long story, but I ll keep it short. After fueling my truck, the low fuel indicator light stayed on - while the gauge did not increase reading AND the info center now reads "--" and not indication of level "low" or tank level. Could it be a coincidence with the fill-up? Could the force of the fuel damage the pump/sender? The pump is AC delco and was swapped 2/2019. Has anybody had this happen? and is it possible the pump plug came lose?

 

[ivin74]

Sounds like the fuel pump sending unit failed, blows my mind an AC Delco pump would go out so soon. If I'm not mistaking the AC Delco warranty is 12 months, I would R&R with another unit before the warranty goes out.

 

[Dan Acosta]

Well, I was able to drop the tank this weekend and the sending unit tested out perfectly 41 ohns to 250 Ohms and contacts were good. SO now what? I have heard a ground? ALso that perhapss I need to clear the PCM or gaueg cluster??

 

[ivin74]

Well, I was able to drop the tank this weekend and the sending unit tested out perfectly 41 ohns to 250 Ohms and contacts were good. SO now what? I have heard a ground? ALso that perhapss I need to clear the PCM or gaueg cluster??

The ohms are within spec.

If the gauge work good before and just failed out of the blue I don't think it's a ground. I would test the wiring harness, the wiring may not be delivering the signal.

 

[ivin74]

Get video

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.youtube.com/watch?v=SIR-quUzZwY&ved=2ahUKEwium4PZ4qLnAhUKG80KHb2iBj0QwqsBMAJ6BAgKEAs&usg=AOvVaw3mjgJHiqL5KEpfMiTkWkB1

 

[Dan Acosta]

Get video

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.youtube.com/watch?v=SIR-quUzZwY&ved=2ahUKEwium4PZ4qLnAhUKG80KHb2iBj0QwqsBMAJ6BAgKEAs&usg=AOvVaw3mjgJHiqL5KEpfMiTkWkB1

That is an informative video. Definately helps to determine where the problem is. I have to imagine someone has experienced the same symptoms I have and how it was addressed. In other words, how do I go about troubleshooting the wiring harness or gauge cluster since it is determined it isn't the sender.

 

[ivin74]

Did you test the sensor wires as shown on the video? If you did and they tested good I would move to the cluster.


Have you notice any of the other gauges malfunction,?speedometer going crazy? If the answer is yes chances are the stepper motors are bad. Get the cluster repaired.

 

[thompsoj22]

That is an informative video. Definately helps to determine where the problem is. I have to imagine someone has experienced the same symptoms I have and how it was addressed. In other words, how do I go about troubleshooting the wiring harness or gauge cluster since it is determined it isn't the sender.

Ill catch flack for this, but completely connect the pump assy outside the tank and go key on eng off and see if fuel low illuminates. i know you dont want to run the pump dry but it will give you a chance to tweak the pump/sending unit connector/float and see if you can affect the problem?