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Juano · 12-14-2021, 04:56 PM

Hi,

I’m having a fuel pump nightmare

Got this 96’ a Bounder 3 months ago and replaced the fuel pump 3 times.

First time I got a pump replacement and installed it on the same assembly as the old pump. Got weak fuel pressure and no sender reading, it showed passing Full every time.

Second time I added an external fuel pump to help to get more pressure, no luck. Still weak.

Now I spent $500 for the OEM
fuel pump, hardwired it so both ground from pump and sender are on the same ground wire coming from the chassis.

Was working great, full of power and reading fuel level perfectly and as soon as I filled the fuel tank the damned gauge on my dashboard went passing Full again and doesn’t seems to get lower with the pass of the days.

I don’t want to drop the tank again pleaseeee, tell that there is something I can do to fix it!

Thanks!

subford · 12-14-2021, 06:54 PM

When the fuel gauge stays passed full all the time means that there is a high resistance from the dash cluster to ground in the fuel gauge circuit. This could be an open circuit in the fuel gauge circuit.

Of course it could also mean the float is stuck in the up position or the the gauge sender not making contact with its wiper to the its Resistor Element part but not very likely.

/

Juano · 12-14-2021, 09:03 PM

Quote:

Originally Posted by subford

When the fuel gauge stays passed full all the time means that there is a high resistance from the dash cluster to ground in the fuel gauge circuit. This could be an open circuit in the fuel gauge circuit.

Of course it could also mean the float is stuck in the up position or the the gauge sender not making contact with its wiper to the its Resistor Element part but not very likely

Thanks again for your help Subford!

So if I understand to check the resistance I should track the yellow wire coming from the fuel pump until it connects to the dash cluster. I use to check resistance with my multimeter set in ohms but not sure how to do it from distances, any recommendation of how to properly do it?

HarryStone · 12-14-2021, 10:20 PM

Same

Juano · 12-14-2021, 10:58 PM

As an extra hint I can say that when the key is on off position the gauge is pointing to Full and few seconds after I turn the key to the ON/ACC position goes further than Full.

THenne1713 · 12-14-2021, 11:15 PM

Gage reading over [F] is a NON-issue in my opinion, and COMMON for most to take quite a while to come down below [F] or come off [F] if it stopped there. I have vehicles that I will never know if the gage goes to [E] or any "Low Fuel" lights come on, because I never allow them to get below 1/2-tank if I can help it? "Take Care of the TOP half and the Bottom half takes care of itself"... you have (at least) a 1/4-tank to run GEN if ever broken down on roadside.. or community disaster use of RV. More important is that it properly displays [E] sometime BEFORE fuel is depleted? ...and w/ RV w/ GEN, that 1/4-tankdisplay is fairly accurate?

subford · 12-15-2021, 05:15 AM

Quote:

Originally Posted by Juano

Thanks again for your help Subford!

So if I understand to check the resistance I should track the yellow wire coming from the fuel pump until it connects to the dash cluster. I use to check resistance with my multimeter set in ohms but not sure how to do it from distances, any recommendation of how to properly do it?

Ground the yellow wire anywhere along its route with the key in the run position.
The needle will (should) go passed "E" while the yellow wire is grounded.

No meter required but start grounding as close to the fuel tank as possible.

DFord · 12-15-2021, 03:47 PM

My previous MH (a 2001 Residency V10) had trouble with the fuel pump and gauge. I found the Siamese power connector failed because it wasn't making good connections and overheated melting itself. I cut it off and replaced it with new 1/4" spade connectors. Drove it another 15 years with the same pump and no problems.

I had to bypass the wire to the sensor from the tank to the rear of the transmission to get the gauge working. I traced the path of the wire and couldn't find any visible issues. I followed the same path with the new wires, wire-tying them to original wiring bundle. The gauge worked great after that.

I knew I had to do something after stopping for gas and putting 74+ gallons in the tank! I had been calculating when to gas up based on the odometer. That's not practicable.

THenne1713 · 12-17-2021, 12:08 AM

RE: GAGE, THINKING FURTHER, CHECK and see if DASH has an INSTRUMENT VOLTAGE REGULATOR feeding the gage/ gages (usually drops GAGE voltage to 5vdc Max); might be worth a few $$ to see if replacement cures your concern? Many were mounted to back of dash, SOME were loose under dash in wiring harness?

Here are some old style pictured: https://duckduckgo.com/?q=automotive...gulator&ia=web

THenne1713 · 12-18-2021, 12:24 AM

FYI, THINKING ABOUT THE FUEL SENDER, IF wire is Grounded anywhere, this will make gage PEG above Full; the send works on the ground wire side of signal. If you can rfind/ reach any wire plug, you can test there?