CORRECTION: Analog *FUEL* gauge not working (temp gauge works fine)

[Randalls84GL1200std]

(Note: this is a repost of my earlier message that I’m making to correct my mislabeling of my bike’s issue in the subject line in the original message. Thanks to Rambozo for calling my attention to the mistake)…

New member (63 years old) AND a proud brand new owner of my very first GoldWing! It’s a gorgeous, pristine 38-year-old Candy Wineberry Red ‘84 GL1200 STANDARD with 31,000 miles under it. Just a couple issues with it…
THE ANALOG *FUEL* GAUGE ISN’T WORKING. Its companion temp gauge is functioning normally so the problem is obviously not the 7-volt regulator that controls the both of them (I’m soon going to purchase one of the site owner’s $39 7-volt regulators just to have it handy if/when the old one fails). Any ideas on what I might look at to get the fuel gauge operational again?
Some background on the bike: The gentleman I just bought the bike from had bought it about a year ago from the widow of the original owner after the bike had sat unused in the original owner’s garage or storage unit for some time and had developed carb and brake issues from sitting so long. Since his purchase of the bike and prior to selling it to me, he got the brakes functional again and had the carbs dismantled, disassembled, and cleaned or rejetted so that it now runs and idles smooth like a brand new electric Singer sewing machine—or like a Honda product. It sure would be nice to have that fuel gauge functional.
The other issue is final drive gear oil leaking from around the bottom of the smooth cylindrical shiny cap just above the center of the final drive case. I haven’t removed the filler plug to check the level yet. I don’t know how it could be overfilled unless someone filled it while it was leaning on the bike’s side stand rather than leveled up on the center stand as the manual states. Assuming it’s not overfilled, is there some other possible issue that would cause gear oil to leak out around that shiny cylindrical cap? I tried twisting that cap to see if it needed tightening but it seems quite tight with no wiggle to it and with no grips to get any real purchase on, I assume it’s not a threaded cap and is pressed in or something? I initially thought it was the filler cap but the manual shows the plug that goes in the sight hole to be the filler cap. And the picture in the manual shows a final drive case that doesn’t even have the shiny cylindrical cap poking straight up on the side of the case that mine has? What’s up with that??
Thanks in advance for any direction or input from anyone familiar with these two areas!

—Randall

[Bike...and Dennis]

The fuel sending unit is probably rusted solid or maybe just the wire is broken somewhere. In either case it should be an easy find and fix. Take the seat off and look down the rabbit hole.

Final drive...don't know.

[Rambozo]

There is an O-ring in that cap that might need replacing.
BTW that cap has been used for something on almost every Honda product as far back as the Super Cub days. It is somewhat delicate and often overtightened. Always use a 6 point tool.

[DenverWinger]

Fuel gauge sender is probably corroded internally. If you ground out the lead going to the sender the gauge should go to the "Full" mark. That confirms the gauge is OK.

Remove sender from the fuel tank and soak it overnight in Vinegar. You'll be amazed how well it will clean up.

[WingAdmin]

Apart from the fuel sender itself being bad, if the fuel gauge is stuck full F, then the wire leading to the sender could be pinched and shorted to ground somewhere along the way. If the fuel gauge is stuck at E, then that wire could be broken or disconnected.

[Randalls84GL1200std]

Gauge shows EMPTY at all times. I haven’t done anything with it yet but planning to pull the sender out of the tank tomorrow evening to have a looksy. If it looks corroded, I’ll try the suggestion that was made to soak it in vinegar overnight and see how that goes. I bought a big jug of distilled white vinegar at Wal-Mart today in preparation for that effort.
Thank you to Bike…and Dennis, Rambozo, DenverWinger, and WingAdmin for your insight and suggestions! I much appreciate it!
—Randall and his ‘84 Candy Wineberry GL1200 Standard

[mito57]

If you ground out the lead going to the sender the gauge should go to the "Full" mark. That confirms the gauge is OK.

Have you tried this? It will tell you with 100% certainty if the sender is at fault.

[stevensacc]

Reading Your post for the same issue, only my gauge is always around half full. Mine does move down a little as the fuel goes down but not much. I tried pulling out the sending unit and took off the cover . Used emery cloth and sanded the contacts. No joy... Guess I'll ground the lead next. But which wire is the lead? Connector has three wires. I'm thinking + ground and gauge. IDK