Fuel Gauge Wonky, Removed Cluster

[donjetman]

Replacing the fuel sender/pump module in the tank didn't fix my fuel gauge with a mind of its own. So today I removed the instrument cluster from the dash and will take it to a local shop tomorrow to see if they can fix it (maybe a bad driver). Maybe even get it customized

http://swtauto.com/

 

[tom3]

Son had several problems with this, finally quit all together. Sent it off to an outfit called Circuit Medics for a rebuild. Nice and bright with all new lamps and all working fine. Was right at $200 for this two years ago.

 

[donjetman]

Local shop loaned me a good used cluster. No change. Fuel gauge in loaner cluster acts wonky too.
Local shop thinks there a bad ground or chafted wire somewhere since I've already changed the fuel pump/sender module.
I ohmed my old sender thru its range of motion and it looked good/linear, no spikes or dead spots.
I'll keep looking for a bad wire/ground under the vehicle.

 

[petethepug]

Grrr, that’s frustrating. Is there a way to get into a harness connector somewhere and connect a new, known working sender to isolate where the issue may be in the harness?

 

[petethepug]

Just a thought. The temp gauge in my 09 will get a mind of its own about every two years then, back to normal.

The only culprit I could narrow it down to was driving in heavy at highway speed. I was going to swap out my battery cables and replace the BCM if it didn’t stop.

Got silverfish in the tank getting on the level sender contacts jumping the circuit?

 

[donjetman]

Got silverfish in the tank getting on the level sender contacts jumping the circuit?

I don't know what "silverfish" is???
I installed new fuel pump and level sender. No change. Inside of tank was clean.

Ohmed the old sender and the graph was smooth.

 

[petethepug]

It’s not u, I have a carton mindset. Silverfish, bugs that look coated with silver powder, at least here in so cal. We always joke about them causing any of our electrical issues around the house.

 

[donjetman]

Ants do that here.

 

[mikez71]

If you need to check wiring, hope this can help..

 

[donjetman]

If you need to check wiring, hope this can help..

View attachment 433107
View attachment 433108

Thanks

 

[mikez71]

Maybe vapor pressure sensor messing with the fuel level signal?