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Fuel gauge issue

Fixitmg

Fixitmg

Member
Joined
Feb 1, 2024
Messages
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Location
Eagle River Alaska
I have a fuel gauge problem that seems simple but still isn't working for me.
I have a 78 snow commander, (I love this Machine)The dash has melted from the amp meter, and can't find another
The sending unit in fuel tank sends a restricted ground to the gauge depending on the amount of fuel in the tank when I bought a aftermarket gauge it should be sending a grounding signal to the gauge but the gauge reads full and I know the truck is about half
I have measured and it dose change resistant depending on the fuel level.
There has to be a way to make this aftermarket gauge work with the factory sending unit.
Has anyone got any ideas
 
You need a gauge that has a range of 10-70 ohms to work. See what your new gauge is. Then go from there.
 
If you have trouble with your after market gauge it's possible to fix an old original one. Even with a bad looking exterior, the interior is often still operational

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Most problems come from connection between inside and outside of the tank. It can be fix easily by tin soldering

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Check resistant before reinstall. Should be near 10 (full) and 70 (empty) as told you Mr.Mopower.

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As a final touch I use the interior of an oil filter to protect aspiration hole

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Factory gauge sending units have the resistor windings not linear. Aftermarket sending units have the sending unit wound linear. this causes gauge reading problems. There is a device (meter match) that is supposed to fix this problem. I have never used one, so can't say how good they are.

MeterMatch Fuel Gauge Interface Module

Tanks, Inc. manufactures fuel system components and polyethylene, steel and stainless steel gas tanks for street rods and special interest vehicles.
www.tanksinc.com
 
So I have ordered the correct aftermarket gauge with the correct OHMs, I never knew that about fuel gauges, I ASSUMED a fuel gauge was gauge like a volt meter, it didn't matter. So i have to thank you guys for the help, when the new gauge comes in i will install it and let you guys know.
 
Charrlie_S said:
Factory gauge sending units have the resistor windings not linear. Aftermarket sending units have the sending unit wound linear. this causes gauge reading problems. There is a device (meter match) that is supposed to fix this problem. I have never used one, so can't say how good they are.
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Click to expand...
Interesting product but price is not enough friendly to buy one just for testing :(
 
Okay gentlemen, The next/current new gauge came in and I installed it and it's better BUT, it reads back words from what I need. At empty it wants to see 70 ohms and full it wants 10ohms. This is back words from what I need.
So the truck has 70 ohms full and 10 ohms empty, which I have measured and know the sending unit is correct.
I have checked on line and can't find a gauge that reads as the truck needs, so is there something I am missing?
This gauge that I just purchased will sweep the gauge as needed but it is back words, when full it reads empty and at empty it reads full. Is there a converter or does anyone know of the exact gauge to use.
The current gauge I bought even had reviews that said they had used it on their old dodge and it worked fine
 
You keep saying "gauge". What did you get? The sender (goes in the tank) or the gauge (goes in the dash)?
The Mopar sender (in the tank) should be about 70 ohms at empty, and about 10 ohms at full. Can you show us what you got? either a picture or what make and part number of the gauge?
 
I don't see the problem. The gauge works and you know it's quark. I drove a Chevy with a Dodge dash for years. Ok, so it made gas untill the tank was empty. Everyone whom drove it knew it worked that way.
I consider it theft prevention. No reason to take a truck with little fuel in it.
 
Sorry guys had other issues come up,
So the link below is the aftermarket gauge I installed. it is suppose to read 73 ohms when empty and 10 ohms when full. which I believe is backwards from what I learned here on this forum. I could not find a gauge that read the other way and a few of the reviews said they had used this gauge on older dodge vehicles and have no problem.
I have the factory sending unit in the tank and it reads almost perfect to what I am understanding
Right now it it is reading about empty on the gauge with 64 ohms, and I believe it to be about 3/4 of a tank. (I have been wrong before)
I hope you guys can help me find the answer to this, I plow with this truck and hate running it out of fuel, in the cold it doesn't like to prime itself really fast.
And by the way the amp gauge caught fire and melted the dash assembly so it has to use a aftermarket gauge till I find a replacement cluster.

https://a.co/d/dEo67cA
 
If you read 64 ohms for 3/4 of a tank, this gauge can't fit your véhicule. You need a 0-90 ohms gauge (0 empty; 90 full)

Your gauge ref is 7361, you should buy the 7362

Equus 7362
 
I don't remember the exact numbers, but the sending unit should read (with a ohm meter) about 60-70 ohms when empty. It should read about 10 ohms when full.
How do you have it wired up? It looks to me like the Equus 7361 is correct.
The factory gauge is wired up with 12v ign power to the CVR. The CVR puts out approx 5 v to the gauge, and the gauge then is wired to the tank sending unit. The tank sending unit needs to have the case grounded.
The equus gauge needs a full 12 volt to the gauge, so you need to disconnect the wire that comes from the factory CVR from the equus gauge, and connect the 12v. Do not remove the factory CVR completely or jumper around it, or the temp gauge will not work properly
 
I installed the aftermarket gauge with a different 12 volt ignition source and the gauge is also grounded
I cut the wire (blue )going to the cluster and ran it directly to the aftermarket gauge
I have to check my fuel and see where the level is right now
I believe it’s 3/4 tank but maybe it is empty now
 
Another wire cutter. Why people do these things. What ever happened to making jumper wires and leaving the original in tact.
 
At this point I need to run this truck down to the gas station and fill it up and watch what happens, so until then I will let you all know as soon as I get the answer.
and as far as cutting the wire, dude if you saw the rats nest under the hood and this truck you won't be too concerned about it. it's a plow truck that the state of Alaska had $6.00 an hour mechanics working on and they never repaired anything they just put bandages on things till they completely broke and then they sold them off.
 
If you plan to fill your tank, it is the best opportunity to read the signal from the sender unit, before and after the tank is full. You will know if you need a 73-10 gauge or a 0-90 gauge
 
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