[ak47dennis]

I am still doing battle with my fuel gauge that won’t read more than 1/8 tank with exactly 18 gallons in the 36 gallon tank. Does anyone have the schematic for the firewall and dash.
I now have good sending unit, removed the tail light harness running to the tank (and rear tail lights) completely unwrapped it inspected, tested it and re wrapped it with the cloth tape.
I am able to read 43 ohms (1/2 tank) on the round dash plug with ignition off, however when I turn the ignition on the ohms drop to approx 15-17.

I believe I have isolated the correct wires in round dash plug, blue w/yellow stripe and the black. I believe the issue is in the black wire.

 

[DODGEBOYS]

Contact me through my site link below


DODGE TRUCKS @ DODGEBOYS.NET-Wiring Diagrams

 

[ak47dennis]

Contact me through my site link below


DODGE TRUCKS @ DODGEBOYS.NET-Wiring Diagrams

Done set up an account with Tap talk what ever it is
Pending approval to your page.

 

[DODGEBOYS]

your all set but you should NOT have had to join just to contact me for a diagram [ see link below ] the contact info is right on the main page

DODGE TRUCKS @ DODGEBOYS.NET-Owner / Admin contact

howdy / if you need to contact me use the email below unlinked [email protected] linked [email protected] the owner [ME} is based in Wes

www.tapatalk.com

 

[volaredon]

Aftermarket sending unit? Good luck getting it to work right

 

[RCCADMAN]

Aftermarket sending unit? Good luck getting it to work right

Maybe he meant the aftermarket sending units that are made for out trucks? Van's and a few other places sell them. I have not bought a new one... yet. I have some that could possibly be rebuilt... maybe? I don't know.

 

[volaredon]

Yup. Junk.

 

[ak47dennis]

Maybe he meant the aftermarket sending units that are made for out trucks? Van's and a few other places sell them. I have not bought a new one... yet. I have some that could possibly be rebuilt... maybe? I don't know.

I do mean the aftermarket senders, I had to purchase 3 of them until they read properly
However with the "good sender" installed and 1/2 tank of fuel my senders is reading proper at 43 ohms, until I turn the ignition on then the ohms reading on the dash display plug falls to 15-17 ohms indicative of an 1/8 tank. Problem now lies some place between the fire wall and display.

 

[SuperBurban]

You cannot measure resistance in a circuit under power, or at least not without measuring voltage, and doing some calculations.

The multimeter works by sending power through the circuit, and measuring the voltage difference. Power already present will effect the readings.

 

[ak47dennis]

You cannot measure resistance in a circuit under power, or at least not without measuring voltage, and doing some calculations.

The multimeter works by sending power through the circuit, and measuring the voltage difference. Power already present will effect the readings.

I should have thought of that duh …
That said the only thing left is to replace the fuel gauge, but as mentioned above the temp gauge pegs like it’s being grounded which leds me to believe their is still a problem and not the gauge.
I am at the end of the road been pulling my hair out on this for months !

 

[SuperBurban]

but as mentioned above the temp gauge pegs like it’s being grounded which leds me to believe their is still a problem

Sorry, I am not the best with this Covid hanging on. I missed that.

What happens if you unplug the sender?

With the dash plugged back in, and the ignition on, measure the voltage in the wire at the temp sending unit.

 

[ak47dennis]

Sorry, I am not the best with this Covid hanging on. I missed that.

What happens if you unplug the sender?

With the dash plugged back in, and the ignition on, measure the voltage in the wire at the temp sending unit.

I actually have the coolant and temp gauge sender wires unplugged, I misspoke it’s oil Presure gauge that pegs with ignition on. 10-4 I will take the voltage readings first thing in the morn

 

[SuperBurban]

You do have the fat sender for a gauge right?

 

[ak47dennis]

You do have the fat sender for a gauge right?

You do have the fat sender for a gauge right?

Yes, I have the correct sender for the 36 gallon tank

 

[ak47dennis]

Sorry, I am not the best with this Covid hanging on. I missed that.

What happens if you unplug the sender?

With the dash plugged back in, and the ignition on, measure the voltage in the wire at the temp sending unit.

Temp sender lead lead shows a pulsing 10 volt while the oil pressure lead shows just pulsing neutral on my power probe

 

[SuperBurban]

Yes, I have the correct sender for the 36 gallon tank

Sorry, I ment the oil pressure sender.

Temp sender lead lead shows a pulsing 10 volt while the oil pressure lead shows just pulsing neutral on my power probe

That is on the high side, it should be closer to volts.

Did you get the wiring diagram? If so can you send it to me so I can figure the next step.

 

[ak47dennis]

Sorry, I ment the oil pressure sender.


That is on the high side, it should be closer to volts.

Did you get the wiring diagram? If so can you send it to me so I can figure the next step.

I replaced oil pressure and temp senders few months ago the appearance was identical to originals. I message Dodge Boys on Tuesday for the needed diagrams and haven’t received a response yet.

Shouldn’t the oil pressure and temp sensor be seeing the same approx. 6 volts like the fuel sender. I have also installed digital voltage limiter in my display.

Thank you for your help, haven’t driven this RC since I got it despite all the work I have done to it I need the fuel gauge to be operable.

 

[SuperBurban]

I replaced oil pressure and temp senders few months ago the appearance was identical to originals. I message Dodge Boys on Tuesday for the needed diagrams and haven’t received a response yet.

Be patient his wife passed recently, and he is going through a big adjustment in life

Shouldn’t the oil pressure and temp sensor be seeing the same approx. 6 volts like the fuel sender. I have also installed digital voltage limiter in my display.

Yes. Was it a do it your self, or bought limiter? The was a weird thing that was done with the wiring for the oil pressure gauge that has caused issues, I am not sure if they still did it in 86 or not. I will see if I can find my copy here.

Thank you for your help, haven’t driven this RC since I got it despite all the work I have done to it I need the fuel gauge to be operable.

How can you have it and not at least drive it around the yard?

 

[ak47dennis]

Be patient his wife passed recently, and he is going through a big adjustment in life Yes. Was it a do it your self, or bought limiter? The was a weird thing that was done with the wiring for the oil pressure gauge that has caused issues, I am not sure if they still did it in 86 or not. I will see if I can find my copy here. How can you have it and not at least drive it around the yard?

It is a purchased plug and play voltage limiter from RTE, its function is very consistent in the way it flashes or regulates the voltage it now has the consistency of blinking Christmas lights.

Haha I have driven it around my yard For now I am not starting it or driving since I have exactly 18 gallons - 1/2 tank I want to keep it that way for testing and calibration.