The Stovebolt Site Forums The Shop Area The Electrical Bay Dancing Fuel Gauge

Has anyone ever figured out how to keep your fuel gauge from dancing all over the place? The only time I get a true reading is when I first get in the truck in the morning. Thanks in advance for the help.

Get a new sending unit and go to church and pray. Praying at home hasn't worked for me. Too much taint from all of the cussing that has taken place in the shop I reckon.

I've been working with a gentleman in China to see about this sender for the AD type tanks. I haven't received it yet because I've been away, but today he should mail it to me. This is a design I tried years ago. I'm curious to see how this one works. The problem you have is (as previously mentioned) is likely your fuel sending unit...however there is an outside chance it could be due to an intermittent ground connection. Resistance to ground is what makes these senders work, Joe. 0 to 30 ohms resistance, actually which is to say you either have no resistance to ground or somewhere between no resistance and 30 ohms of resistance. The sender I liked the best is evidently no longer available. It was designed and made in Taiwan and it was excellent. This one has promise. If you want to wait until I get it, that should be fine.

https://www.ebay.com/itm/196803441317

Jon G:

I ~think~ this is the design you liked?

https://www.amazon.com/Level-Sender-Sending-ranges-Adjustable/dp/B087BDDTX7

Different seller and probably different country of origin.

You know I had similar issue after reconditioning the induction cluster because I painted the inside of the house and that prevented the gauge from having a good ground.

When the tank is only partly full, the gauge jumps up and down on bumpy roads due to the gas sloshing around in the tank. If the gauge had a damper it might help. Just another old car quirk...

My '37 jumps around, the gauge is just loose. When I had mine out recently, you could just twist your wrist and make the needle go from full to empty pretty quickly. I quit looking at it!

I have checked all grounds. They have good connection. When completely full needle barely moves. As gas gets lower the needle dances. I am aware it is the float moving with the gas as it sloshes around. Just wondered if anyone had come up with a fix, other than a new tank with baffles built in.
Thanks for the responses.

Get a new sending unit, the 30 ohm one sold by a guy named industrialstuffs on ebay. It's the only one recommended by Stovebolt mad scientist, Jon G.

Yes, the one shown on Amazon in JW51's link is an excellent sender. Here is why I like it:
1---the wiper is traveling on a flat surface and not inside a C shape (those frequently lose connection)
2---the resistance disc is made of a resistance arc connected to tiny metal "fingers" so they're going to last longer because the wiper doesn't constantly erode the resistance medium. In a perfect world flat resistance wire would be used (and I made several of these) but that process is time consuming. It does however create a very accurate variable resistor.

Please take a look at what I was sent by one of the usual suspects of aftermarket sellers (I won't mention them by name but some folks here seem to like them). It was sold as a 0 to 30 ohm sender and the way the maker did that was to drop globs of solder on to a 0 to 90 ohm sender until the resistance was lowered to 30 ohms. This meant the unit was completely unable to register correctly because at points the fuel level would seem to not change and then suddenly you'd realize you had less fuel. Good luck!

Also, very important...there will be a sheet with the sender I suggested. It will tell you how deep to cut the mast (the central vertical part) which is based on the depth of your fuel tank and how long to cut the rod holding the float based on the length of the mast. This will ensure your float registers the proper fuel levels. If your tank is in good nick, you don't need to replace it. Some of these tanks had a baffle at the bottom (so you wouldn't run completely out of gas) but some didn't and none that I've seen were baffled horizontally.

A wiggly gauge needle should make you happy just like an engine that leaks oil.
It means that you have enough of both oil and gas to make it most of the way home.

I can bare witness to just how much PaPa Joe’s gauge dances around. On our jaunt to the AD Nationals it was very apparent it wasn't reading steady.

I have used the type of resistance sending unit that Jon was talking about. The HUMMVs we had in the Air Force used this type. These were 24v and 0 - 90 Ohm resistance. Very accurate and steady.

Excellent points. I just assume the middle of the wiggle is the right level. Even if the needle is steady, the ambiguous markings on the AD gauge leave plenty of mystery.

The gauge is pretty decent at telling me I have less gas than when I started driving. And it tells me I have more gas after a fill up than I did before I stopped.

😝

That is what I have been doing. Middle of the wiggle is the true reading. And I have found that when the needle stops wiggling at the empty mark, I have about 2 gallons left. I may try to adjust that so I have at least 3 gallons left.
Just to give myself more wiggle room. Pun intended. 😂

Jon, per second post in this thread do you have any updates on latest sending unit option?
My 46 w tank under seat did not like the renbuson unit, I think the 7” deep tank cut the arm sooo short it did not actuate/float well.
Chuck

Chuck I thought the fellow in China had sent me one but there was some confusion. I have been in/out of town and hope to hear from him soon. He has one that might work okay in your 7 inch deep tank. It would register empty by my calculations when you had 1.5 inches of gas still in your tank...which ought to be enough not to leave you stranded. Here is his eBay auction for it:

https://www.ebay.com/itm/196836956438

Please let me know...if you want, you could wait until I get one to see how it performs. The way it works the action should be better for a 7 inch tank I would think.
Jon

After your prev post I went to his eBay store and saw that sender, I will keep you informed if I get around to ordering before you get one…

Chuck

So, is 7" the stock height for our AD truck tank? Jon if you have good luck with this sending unit, I will jump on and get one as well. Thanks for posting the info

7” is for the 46 truck as it has the tank under the seat. Your tank may be in different location ( behind seat) and use a different depth sensor.
Chuck

Craig the stock AD truck tank is...well, I've seen several that were baffled about an inch or two from the bottom. That is to make sure your gauge registers empty when there is still enough gas in the tank to get you somewhere (hopefully). And I've seen a few that had no baffle at all. I would suggest removing the sending unit and measuring down in the tank to the bottom. It ought to be 10 3/4". That translates into right at 274mm and so it seems to me the 260mm unit he makes is probably the best option for the stock AD trucks. Chuck's tank is under the seat and is 7 inches deep (which is different). I have one on the way (260mm) and will let folks here know.

Awesome. Thanks Jon and Chuck