When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My fuel gauge on my 77 F250 single cab 4X4 is always reading E or just above E, I did the trick of removing the wire from the sending unit and ground it out to see if the gauge would read full however that didn't happen. I tried to trace the wires leading from my main tank and am quickly getting lost in the mess of wires. to make things a bit worse the PO seemed to make a change to the fuel delivery system by bypassing the solenoid that would switch between the main and aux tanks. I also have a wire that is hanging down next to the solenoid that I'm not sure what it goes to. any help or suggestions would be appreciated.
Does the temp gauge do anything similar? Is there an oil pressure gauge? Just trying to rule out your Instrument Panel Voltage Regulator.
If you can ground your sender wire from a point in the wire which is closer to the gauge itself, and it then pegs hot, you will have isolated the problem to the dual-tank spaghetti...
that dangling wire looks like what connects to your sending unit. You sure the sending unit is even attached? One very useful diagnostic tool is a long piece of wire with alligator clips on the ends; allows you to bridge past confusing wire harnesses.
I agree with HoustonDave, the wire hanging there is the Aux tank sender harness.
Make sure your dash fuel tank switch is on the proper tank(sender) that you are grounding out.
Fuel switch on Aux, ground out that hanging wire and you should peg your gas gauge to F; switch back to main and your gauge should drop to E.
Fuel switch on Main, ground out the main tanks sender and you should peg the fuel gauge; switch to Aux and you're back at E
That solenoid has three plumbed connections,(should be marked on the nipples) one from the main tank, one from the AUX tank and 1 to the fuel pump.
Those tank solenoids have a way of "sticking" if they are not used regularly.
1st check for 12v on the solenoid wire.
If you have 12v present, re-attach that lead and have someone flip the tank switch on your dash from main to aux a few times while you listen to the solenoid.
You should be able to hear the solenoid activate; if no sound try tapping it gently with a hammer.
If still no sound then you have a stuck solenoid and it needs replacing.
You could probably get that set up again fairly easily if you have two good tanks.
Tbruz
Last edited by tbruz; May 11, 2017 at 08:31 PM.
Reason: typo
Does the temp gauge do anything similar? Is there an oil pressure gauge? Just trying to rule out your Instrument Panel Voltage Regulator.
If you can ground your sender wire from a point in the wire which is closer to the gauge itself, and it then pegs hot, you will have isolated the problem to the dual-tank spaghetti...
My temp gauge does work on my instrument cluster, I'm not sure how to get my dash apart yet, can you direct me to a video or an tutorial?
that dangling wire looks like what connects to your sending unit. You sure the sending unit is even attached? One very useful diagnostic tool is a long piece of wire with alligator clips on the ends; allows you to bridge past confusing wire harnesses.
Both my main and my aux fuel tanks have wires attached to their sending units. would this wire go some where else?
I agree with HoustonDave, the wire hanging there is the Aux tank sender harness.
Make sure your dash fuel tank switch is on the proper tank(sender) that you are grounding out.
Fuel switch on Aux, ground out that hanging wire and you should peg your gas gauge to F; switch back to main and your gauge should drop to E.
Fuel switch on Main, ground out the main tanks sender and you should peg the fuel gauge; switch to Aux and you're back at E
That solenoid has three plumbed connections,(should be marked on the nipples) one from the main tank, one from the AUX tank and 1 to the fuel pump.
Those tank solenoids have a way of "sticking" if they are not used regularly.
1st check for 12v on the solenoid wire.
If you have 12v present, re-attach that lead and have someone flip the tank switch on your dash from main to aux a few times while you listen to the solenoid.
You should be able to hear the solenoid activate; if no sound try tapping it gently with a hammer.
If still no sound then you have a stuck solenoid and it needs replacing.
You could probably get that set up again fairly easily if you have two good tanks.
Tbruz
I had my wife move the switch for my fuel tanks back and forth while I was under the vehicle and never heard the solenoid make a noise nor did I feel and thing from it. I tried grounding out the wire i pulled off of my sending unit from my main tank and received no change in my gauge, I also rocked the switch back and forth between main and aux several times waiting for several seconds to see if a change would occur. could that wire need to go some where else other than the sending units?
My temp gauge does work on my instrument cluster, I'm not sure how to get my dash apart yet, can you direct me to a video or an tutorial?
Reach up under the dash and find the little release button on the light switch and pull the light switch **** and shaft out, all the way out of the switch. Your lights will be on, so gently push it back in until they turn off, parking lights too, and then pull it back out. Then get a flatblade screwdriver and get behind the wiper ****. There's a little clip, and if you push it toward the **** from the right spot, while pulling the **** out, it will come off.
Then you have the little screws which hold the bezel, mostly visible when you look from underneath. Remove those, and depending on your radio, the whole bezel should come off - lift up a little. The bezel will be tethered by the wires to the light for your Lights and Wiper switches, but the bulb holder simply clips on, and is easy to remove.
Everything in the dash looks pretty straightforward, four screws for the cluster, HVAC, radio, etc...
Check out these sticky threads: https://www.ford-trucks.com/forums/1...then-some.html
and https://www.ford-trucks.com/forums/1...mpilation.html
Not quite a Haynes Manual, but in some ways better!
whole list of questions....
1) Do the connectors pushed onto the sending units appear similar to that hanging connector? They should be.
2) Are they, and the hanging connector, single or two-terminal connectors? Fuel senders use connectors with two round male posts; the wiring harness connector should have two round female.
3) Check all of those harness connectors - each should have one grounded side and one 'pulsing' side. If you use a standard 12V test light, when the clip is hooked to ground poke the probe into the female connectors; one should cause the light to light and dim repeatedly.
4) I believe the solenoid wire is activated by the switch (I have one big tank; someone correct me if I'm wrong) - using the test light see if that wire becomes hot when your tank switch is flipped. Might be a momentary pulse - again, I only have one tank.
5) Check and clean the grounds. Again. If you have a multimeter, check continuity through the ground wires to be sure what starts at a connector as a ground makes it all the way to the frame as a ground.
My fuel gauge on my 77 F250 single cab 4X4 is always reading E or just above E
I did the trick of removing the wire from the sending unit and ground it out to see if the gauge would read full however that didn't happen.
The fuel sending unit float is made of two pieces of brass soldered together. Solder breaks down, gas seeps in, float settles to the bottom of the tank.
Float is available from Ford & repro parts sellers. It's the same: 1957/79 FoMoCo Passenger Cars & Trucks, 1961/79 Econolines and 1966/79 Bronco's.
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
