Bad New Sending Unit or Something Else?
Thread Starter
|
Cross-Country
Joined: Dec 2019
Posts: 52
Likes: 3
Bad New Sending Unit or Something Else?
Hi everyone. My fuel gage stopped working about 2 years ago in my 61 F-100, and I finally got around to getting a sending unit for it. It's an Auto Metal Direct, which ran me about $50. I put it in and even with a full tank, it only reads to about 3 quarters of a tank. I took it out and tried moving the arm by hand, and it's the same. If the fuel drops a little bit, it reads less than a quarter or empty. I checked the ground, and it was good. I even tried running a new ground, and that didn't help either. The test light lit up when I tried that as well, so it's getting power. Was just wanting to know thoughts before I try and take it back to return it to NAPA.
Mountain Pass
Joined: May 2023
Posts: 126
Likes: 13
Hi everyone. My fuel gage stopped working about 2 years ago in my 61 F-100, and I finally got around to getting a sending unit for it. It's an Auto Metal Direct, which ran me about $50. I put it in and even with a full tank, it only reads to about 3 quarters of a tank. I took it out and tried moving the arm by hand, and it's the same. If the fuel drops a little bit, it reads less than a quarter or empty. I checked the ground, and it was good. I even tried running a new ground, and that didn't help either. The test light lit up when I tried that as well, so it's getting power. Was just wanting to know thoughts before I try and take it back to return it to NAPA.
Tuned
Joined: Aug 2021
Posts: 274
Likes: 63
If you ground the gauge wire to the tank with the key on, it should read full. It appears that your gauge is working. The sending unit not so much.
I believe there is an ohms test for the sending unit in the manual IIRR. Maybe someone here knows what the readings should be.
Tom
I believe there is an ohms test for the sending unit in the manual IIRR. Maybe someone here knows what the readings should be.
Tom
Tuned
Joined: Aug 2021
Posts: 274
Likes: 63
Maybe you have a buddy that knows how, or The U Tube may be your friend.
There are 2 more things that can/may cause your issue. My '62 would only read just over 3/4 with a very full tank.
I replaced the voltage regulator for the DASH because my old one tested like it was shot. Didn't fix the fuel gauge.
Pulled the gauge wire and grounded it to the tank, full tank.
Pulled the sender and tested it. Found that it would not read correctly for a full tank. Also while it was out I grounded it and hooked up the gauge wire and moved the float, still 3/4. Hmmmm??
Noticed there was a stop that would keep the wire for the float from moving anymore. Noticed I could carefully bend it. Tried just a touch, gauge showed a bit higher, after a few more touches, the gauge reads full when full. I do not know if this will help you or not.
I do find it odd that the wire and float may have never let the gauge read full when it left the factory???
Tom
There are 2 more things that can/may cause your issue. My '62 would only read just over 3/4 with a very full tank.
I replaced the voltage regulator for the DASH because my old one tested like it was shot. Didn't fix the fuel gauge.
Pulled the gauge wire and grounded it to the tank, full tank.
Pulled the sender and tested it. Found that it would not read correctly for a full tank. Also while it was out I grounded it and hooked up the gauge wire and moved the float, still 3/4. Hmmmm??
Noticed there was a stop that would keep the wire for the float from moving anymore. Noticed I could carefully bend it. Tried just a touch, gauge showed a bit higher, after a few more touches, the gauge reads full when full. I do not know if this will help you or not.
I do find it odd that the wire and float may have never let the gauge read full when it left the factory???
Tom
Logistics Pro
Joined: May 2015
Posts: 4,469
Likes: 965
From: Tri Cities, TN
Fuel gauge
If your other gauges are working correctly the test will tell whether you have a bad gauge or bad sender.
Fuel gauge issue - Ford Truck Enthusiasts Forums (ford-trucks.com)
Trending Topics
Thread Starter
|
Cross-Country
Joined: Dec 2019
Posts: 52
Likes: 3
Maybe you have a buddy that knows how, or The U Tube may be your friend.
There are 2 more things that can/may cause your issue. My '62 would only read just over 3/4 with a very full tank.
I replaced the voltage regulator for the DASH because my old one tested like it was shot. Didn't fix the fuel gauge.
Pulled the gauge wire and grounded it to the tank, full tank.
Pulled the sender and tested it. Found that it would not read correctly for a full tank. Also while it was out I grounded it and hooked up the gauge wire and moved the float, still 3/4. Hmmmm??
Noticed there was a stop that would keep the wire for the float from moving anymore. Noticed I could carefully bend it. Tried just a touch, gauge showed a bit higher, after a few more touches, the gauge reads full when full. I do not know if this will help you or not.
I do find it odd that the wire and float may have never let the gauge read full when it left the factory???
Tom
There are 2 more things that can/may cause your issue. My '62 would only read just over 3/4 with a very full tank.
I replaced the voltage regulator for the DASH because my old one tested like it was shot. Didn't fix the fuel gauge.
Pulled the gauge wire and grounded it to the tank, full tank.
Pulled the sender and tested it. Found that it would not read correctly for a full tank. Also while it was out I grounded it and hooked up the gauge wire and moved the float, still 3/4. Hmmmm??
Noticed there was a stop that would keep the wire for the float from moving anymore. Noticed I could carefully bend it. Tried just a touch, gauge showed a bit higher, after a few more touches, the gauge reads full when full. I do not know if this will help you or not.
I do find it odd that the wire and float may have never let the gauge read full when it left the factory???
Tom
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
Tuned
Joined: Aug 2021
Posts: 274
Likes: 63
So if your saying that with a "full tank at the gas station pump" and you squeezed all you can into it. The gauge reads 3/4. Then you drive 5 or 10 miles and it reads nearly empty. I would think the sender is bad. I just brought up an issue that I had. My gauge always went down smoothly while driving 100 miles, it DID NOT just drop off to empty..
You would need to hook up a volt meter set to ohms to the sender and check the ohms for the correct readings per the manual. You could have a defective sender.
If the ohms test is not possible, then just get an exchange and see what happens. Just make sure that you did get the correct sender and the correct exchange.
Best of luck and please let us know what happens!
Tom
You would need to hook up a volt meter set to ohms to the sender and check the ohms for the correct readings per the manual. You could have a defective sender.
If the ohms test is not possible, then just get an exchange and see what happens. Just make sure that you did get the correct sender and the correct exchange.
Best of luck and please let us know what happens!
Tom
Tuned
Joined: Aug 2021
Posts: 274
Likes: 63
This got me thinking. 3-4 to empty?????
I just wanted to make sure..... If you fill up the tank and it reads 3/4, then you drive it 10 miles and it reads nearly empty. Now you go back to the gas station and fill it up again. What does it take, should be about 1 gallon or less.
If it takes like 10 gallons, then you have a major fuel leak somewhere. You should smell it and see it on the ground or at least the crank case would be WAY over full.
Sorry, just thinking about this.
Tom
I just wanted to make sure..... If you fill up the tank and it reads 3/4, then you drive it 10 miles and it reads nearly empty. Now you go back to the gas station and fill it up again. What does it take, should be about 1 gallon or less.
If it takes like 10 gallons, then you have a major fuel leak somewhere. You should smell it and see it on the ground or at least the crank case would be WAY over full.
Sorry, just thinking about this.
Tom
Tuned
Joined: Aug 2021
Posts: 274
Likes: 63
I wanted to add this in a separate post so it didn't get lost in a long post.
Your gauge could be bad. The simple test for a gauge is to ground the wire to the sender. The gas gauge should read full. It it reads anything else, it would likely be bad.
I would think the manual also has a gauge test.
You really need to test then sender, at least to me that is the most likely suspect.
There are people here with WAY more expertise in this than I am. I hope one of them would add to this. Cropduster did, by saying you need to learn how to use the volt meter and a link to testing your issue.
Hope you get this solved and it just a faulty sender
Tom
Your gauge could be bad. The simple test for a gauge is to ground the wire to the sender. The gas gauge should read full. It it reads anything else, it would likely be bad.
I would think the manual also has a gauge test.
You really need to test then sender, at least to me that is the most likely suspect.
There are people here with WAY more expertise in this than I am. I hope one of them would add to this. Cropduster did, by saying you need to learn how to use the volt meter and a link to testing your issue.
Hope you get this solved and it just a faulty sender
Tom
Logistics Pro
Joined: Jun 2018
Posts: 3,553
Likes: 442
If your sender has corrosion on it That is a problem that you can fix with a a light sand with some 120 wet & dry. The sender is nothing more than a rheostat that changes ohmic value. If your gauge changes dramatically there is a dead spot in the rheostat. Time to clean it up or replace it.
.
.
Thread Starter
|
Cross-Country
Joined: Dec 2019
Posts: 52
Likes: 3
So if your saying that with a "full tank at the gas station pump" and you squeezed all you can into it. The gauge reads 3/4. Then you drive 5 or 10 miles and it reads nearly empty. I would think the sender is bad. I just brought up an issue that I had. My gauge always went down smoothly while driving 100 miles, it DID NOT just drop off to empty..
You would need to hook up a volt meter set to ohms to the sender and check the ohms for the correct readings per the manual. You could have a defective sender.
If the ohms test is not possible, then just get an exchange and see what happens. Just make sure that you did get the correct sender and the correct exchange.
Best of luck and please let us know what happens!
Tom
You would need to hook up a volt meter set to ohms to the sender and check the ohms for the correct readings per the manual. You could have a defective sender.
If the ohms test is not possible, then just get an exchange and see what happens. Just make sure that you did get the correct sender and the correct exchange.
Best of luck and please let us know what happens!
Tom
I'm not sure if I can even return it to NAPA since it was a special order from Summit Racing.
Thread Starter
|
Cross-Country
Joined: Dec 2019
Posts: 52
Likes: 3
I watched a quick tutorial and I think I got the voltage meter set up right. I put the red probe on the post with the wire going to the gauge, and the black probe on the post with the ground wire and it was showing 2 (ohms, I'm guessing?) Does that sound right to you?
Lead Gopher
Joined: Aug 2012
Posts: 10,057
Likes: 1,612
From: Seattle
Dennis Carpenter lists the ohms range for full and empty tank.
Gas Fuel Tank Sender Unit for 1961-77 Ford Trucks | Dennis Carpenter Ford Restorations (dennis-carpenter.com)
Gas Fuel Tank Sender Unit for 1961-77 Ford Trucks | Dennis Carpenter Ford Restorations (dennis-carpenter.com)