Fuel gauge (dual tanks)

[StickDeath]

no its not all the way down there its a far as it will go down. not broken just not getting signal

 

[Boone83K10]

pic?


sounds like the gauge is broken internally. I bet you have a bad ground which takes it to 3 o clock and something broken internally on the gauge and that takes it to 6 o clock.

 

[StickDeath]

pic?


sounds like the gauge is broken internally. I bet you have a bad ground which takes it to 3 o clock and something broken internally on the gauge and that takes it to 6 o clock.

i get off work in a few and i will put up a pic after. About an hour

 

[StickDeath]

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[Busaman]

I agree with Boone I bet its a broken gauge.

 

[Boone83K10]

Yeah that is going the opposite way I was thinking.

That is almost like you have a NEGATIVE resistance.

The gauge reads 0 - 90 ohms. FULL is 88 ohms, Empty is ZERO ohms. When you have a broken wire or bad ground it reads INFINITE ohms and goes to 3 o clock position past the FULL mark. Yours' is going the opposite way.

Read this...

FUEL GAUGE FUNCTIONAL TEST

FUEL LEVEL GAUGE PARAMETERS

For Truck Years: 1967 - 1990

The Fuel Gauge Needle Should Point to:
Left Line (Empty) when sender resistance = ~1 Ω
Middle Line (Half) when sender resistance = 44 Ω
Right Line (Full) when sender resistance = 88 Ω

Referring to the fuel gauge chart, above, notice that the resistance of the fuel tank sender gradually increases to about 90 Ω as the fuel gauge needle swings toward "Full." Logically, if the resistance of the fuel tank sender circuit increases above 90 Ω, the fuel gauge needle will continue to swing past ‘Full.’ As it happens, when the fuel sender circuit develops an "open" (which is a loss of electrical connection or continuity, such as a disconnected or broken wire, a worn out or corroded sender, or a corroded sender ground connection), the fuel gauge needle swings well past ‘Full’ and finally settles, pointing roughly toward the 3:00 o’clock position.

Conversely, if the fuel sender wiring between the sender and the gauge "shorts to ground," the fuel gauge needle swings to "Empty." So, an ‘open’ in the fuel gauge sender wiring, anywhere between the dash gauge and the sender ground connection to the frame, will cause the fuel gauge to pin to the right, past "Full." Whereas, ‘grounded’ sender wiring anywhere between the fuel gauge and the tank sender will force the fuel gauge to continuously indicate "Empty."

Troublesome corrosion of automotive fuel tank senders and accelerated deterioration of rubber and plastic fuel system materials has become prevalent, since alcohol was introduced into fuel formulations.

 

[Boone83K10]

So from the above post, we can deduct that you have a short to a ground.

Here is the schematic for 73-80 Dual Tanks. Check the wiring for shorts.

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[StickDeath]

. There are some wires that where all shorted out looking. back at the value under the truck. SO and they were just cut and dangling down so i black taped them and zip tie out of the way. Should the fuel tank sending unit wires just run along side the frame?

i will check it out this weekend sounds like that might be it thanks.

 

[Busaman]

Where do you get those schematics? My hanes manual prints suck.

 

[Boone83K10]

well that wiring diagram doesn't apply to our (83-87) dual tank setup.


I have them saved on my google drive

Here is 83-87 if you want it.

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[Boone83K10]

. Should the fuel tank sending unit wires just run along side the frame?

i will check it out this weekend sounds like that might be it thanks.

yes they are just kind of laying there. I wonder if you taping them together is causing some trouble. Never know with electrical stuff.

 

[cedens]

I have yet to tackle my tank switch issue, hit the switch "depress fully" and nada.... either its a $13 switch or a $90 solenoid valve

 

[Boone83K10]

If you dont hear a click from under the truck when you press the button..then its the solenoid.

Sent from my SCH-I535 using Tapatalk

 

[1984K10]

Anyone know if you have to take the bed or can off to take the selector valve off and replace it?

 

[chengny]

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REMOVAL:
The auxiliary fuel tank control valve is located under the right hand side, center of vehicle, attached to the inner side of the frame.



1. Disconnect negative battery cable from vehicle battery.
2. Raise vehicle.
3. Remove hose shield, when required.
4. Remove electrical connector from valve and switch assembly.
5. Remove fuel feed and return hoses. Note position and color markings on hoses.
6. Remove selector valve and meter switch from frame.

INSTALLATION:



1.Install the selector valve and meter switch to the frame.
2.Connect the fuel feed and return hoses, taking care to install hoses in the correct positions.
3.Connect electrical connector to valve and switch assembly.
4.Install hose shield, when required.
5.Lower vehicle.
6.Reconnect negative battery cable to vehicle battery.
7.START vehicle and allow to run while checking for fuel leaks.