Dual Fuel Tank Question

84K30 said:

I believe I may have identified part of the issue... the ground wire which connects the fuel sending unit to the body is broken. Does anyone have a photo of where/how the wire connects to the sending unit?

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I just looked at this on mine and it is clipped onto the sending unit or lock ring. I'd maybe consider soldering it to a tab on the top of the sending unit.

IIRC, there is a tab on the sending unit and the connector for the ground wire is crimped on it. The other end of the ground wire has a ring terminal for grounding it to the frame.

Bruce

When I cleaned my tanks, one tank came off the jack and yanked the ground wire off. I just cleaned it up with a brush and soldered it to the post where it broke off.

If you cant solder it back on, drill a 3/16" hole through the tab and fit it off with a crimp terminal.

I appreciate all of the responses. Duster dude, if you wouldn’t mind sending me/posting a picture of where exactly the wire connects to the sending unit, I would appreciate it. I don’t recall seeing anything that appeared to be a broken connection/solder when I removed the sending unit to clean the tank.

The ground wire was still bolted to the body when I removed the tank.

I am also considering replacing the sending unit itself since that resolves my broken wire issue and would add a sense of confidence that the pump is new.

It doesn't matter where the ground wire attaches, as long as it attaches somewhere. In the past when the wire has broken off, I've drilled an 1/8" inch hole in a lock ring tab, then installed the wire with an eyelet screwed to that tab with a short #8 screw.

The wire is soldered or somehow attached to the nub on the sender

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Thank you for posting the picture the attachment point, dusterdude . If I were able to solder/screw the wire back on without dropping the tank again I would absolutely would. However, seeing as how the tank has to come out regardless, I went ahead and ordered a new AC Delco sending unit. I figure that is the route to go since that also eliminates the sender as a factor if my issue persists after resolving the missing ground situation.

I'll keep yinz posted.

You're welcome dude,hope you get it straight

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Got around to replacing the passenger fuel tank sending unit today. The new unit included that ground wire I had previously asked about. Went ahead and replaced the rubber fuel hoses between the sending unit and hard lines while I had the tank dropped. I also replaced the fuel tank selector switch.

Even after replacing the items mentioned above, the fuel gauge pegs beyond "F" when I depress and hold the selector switch in the "RH" position. This is with about 5 gallons in the tank. I filled the tank (in the event the float was stuck in the up position) and put fuel stabilizer in it since were about ready for winter here in Pennsylvania. I also figured the tank shouldn't have to come out again since everything has been replaced. When the switch is held in the "LH" position, it reads accurately.

I hear a faint humming noise that I believe to be the fuel tank selector/diverter valve when I depress the tank selector switch. Should this be happening? Does anyone know of a fuse or maybe another ground that may be causing my symptoms, it seems like an electrical issue.

Would it be worth replacing the selector/diverter valve since I do not know if it is operating correctly?

Thank you,
Eric

I would check / clean your connections at the valve. You should hear a clunk when it is switched, if not then replace it.

The noise it makes is absolutely not a clunk. I'll just go ahead and replace it.

The valve currently on the truck appears to have been replaced with AcDelco U7001 (7 port, 1 of which is unused) The weather pack style 6 pin connector appears to be in good shape. I'll give it a spray with electrical parts cleaner just to be sure.

I would go on and replace the valve itself. The electrical connection goes through the valve.
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Upon looking at the 10 day forecast, I came to the conclusion that today was likely going to be the last day that I will be able to drive my truck until spring. I started my truck with the tank selector switch in the R/passenger tank position and let it warm up a few minutes before driving. The gauge read beyond "F" as I mentioned it has since I started troubleshooting this issue. After about a mile driving, the engine began to surge as if it were about to stall.

I depressed the selector switch in position that coincided with the L (driver's side tank), the gauge needle shifted to the "F" position which was accurate. The engine smoothed out and I made it to my destination. When I got home, I played with the switch with the key on but engine off (accessory mode) and noted a dicernible clunk that Termite_Delight mentioned in his post. The fuel tank reading shifted between "F" when the switch was in the left tank position and significantly beyond "F" when in the right tank position.

I have yet to replace the valve but received it via Amazon today and intend to swap it out this Thursday. If the above information give anyone any ideas of what else to check, I would certainly appreciate any suggestions.

Thanks,
Eric

Removed the old selector valve today, and measured and cut new rubber fuel lines between the valve and hard lines.

I pre-installed the rubber lines on the new selector valve since I assumed it would be easier to do before it was mounted up to the frame. However, when I went to mount the new valve to the frame, I discovered that I couldn’t get my hand past the rubber hoses to tighten the mounting bolts. When I went to remove the rubber hoses, one of the plastic nipples on the new valve broke.

I have another valve on the way. Hopefully the rest of the install goes smoothly.

Eric