Fuel gauge stuck on full
Thread Starter
|
5th Wheeling
Joined: Jun 2023
Posts: 27
Likes: 0
Fuel gauge stuck on full
Alright... so I've been trying to figure out my speedo issues (that will probably be another post another day lol) so I've had the cluster out and have unplugged the speedo cable from the back of the cluster a couple times.
Now I just realized that my fuel gauge is stuck showing past full on both tanks. If I turn the key on the gauge goes about a quarter of an inch past full, and with the key off it drops to right above full. I know it isn't because of the sending unit (it is new) and it was working fine until I was messing with the gauge cluster today. All of the other gauges work fine, it's just the fuel gauge.
Anyone able to help me out here?
Now I just realized that my fuel gauge is stuck showing past full on both tanks. If I turn the key on the gauge goes about a quarter of an inch past full, and with the key off it drops to right above full. I know it isn't because of the sending unit (it is new) and it was working fine until I was messing with the gauge cluster today. All of the other gauges work fine, it's just the fuel gauge.
Anyone able to help me out here?
Moderator
Joined: Jan 2001
Posts: 56,946
Likes: 2,717
From: Virginia
Yes, what are you working on? And generally speaking, I have had that happen before and come to find out I didn't get the cluster plug seated all the way back in. Another general rule, if it was working before you messed with it, and now it's not, it is certainly something you did that caused it. Just retrace your steps.
Thread Starter
|
5th Wheeling
Joined: Jun 2023
Posts: 27
Likes: 0
Sorry yeah I realize I completely forgot to put what vehicle, 89 f150
So I know it is something to do with the cluster, I swapped in the cluster from my 89 f250 parts truck and the fuel gauge worked properly. So now it's just figuring out what I did to my original cluster 🤔
So I know it is something to do with the cluster, I swapped in the cluster from my 89 f250 parts truck and the fuel gauge worked properly. So now it's just figuring out what I did to my original cluster 🤔
Moderator
Joined: Jan 2001
Posts: 56,946
Likes: 2,717
From: Virginia
An 89 was exactly what I was working on. Like I said, I found I hadn't seated the wiring plug in fully. You may also want to inspect the copper that is glued to the plastic where the connector is located. The copper likes to come loose and wrinkle up where the plug goes in. I have straightened it out and then super glued it back to the plastic with pretty good success.
Thread Starter
|
5th Wheeling
Joined: Jun 2023
Posts: 27
Likes: 0
Well now I'm even more stumped. Yes, I make sure the plugs are seated correctly, and the copper strips look fine too.
So I tried swapping the cluster from my parts truck again, and as I was playing with switching the fuel tanks I noticed that sometimes if I flip to the front tank the gauge goes all the way to the top. If I flip back to the rear and let the gauge go down to the level the rear is at and then flip back to the front, the front will then usually read correctly, but if I quickly flip through it goes to the top only on the front tank..
So I tried swapping the cluster from my parts truck again, and as I was playing with switching the fuel tanks I noticed that sometimes if I flip to the front tank the gauge goes all the way to the top. If I flip back to the rear and let the gauge go down to the level the rear is at and then flip back to the front, the front will then usually read correctly, but if I quickly flip through it goes to the top only on the front tank..
Thread Starter
|
5th Wheeling
Joined: Jun 2023
Posts: 27
Likes: 0
Another update...
Parts truck gauge is working like normal at the moment so ill be running it for the time being (although the temp gauge doesn't work).
As for the original cluster I had plugged it back in after trying to clean some of the copper and now the gauges go up about half an inch over full... the needle is horizontal now. Have no clue what I did.
Parts truck gauge is working like normal at the moment so ill be running it for the time being (although the temp gauge doesn't work).
As for the original cluster I had plugged it back in after trying to clean some of the copper and now the gauges go up about half an inch over full... the needle is horizontal now. Have no clue what I did.
Trending Topics
Moderator
Joined: Jan 2001
Posts: 56,946
Likes: 2,717
From: Virginia
What engine do you have? Some have a 6 port valve on the frame with lots of wires, others are fuel injected and have a 6 port that has no wiring going to it. The ones with about 5 or 6 wires actually switch the sending units inside the valve. So you may have a problem with the valve on the frame, very common. If you have a fuel injected truck and have the valve on the frame with no wires, your sending units are switched by the switch in the dash. I have had them go bad also.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Moderator
Joined: Jan 2001
Posts: 56,946
Likes: 2,717
From: Virginia
Ok, then your sending units are switched by the dash switch. They can get old and dirty. Not sure if you can buy a new one or not. If you never plan on running dual tanks again, you can probably get a diagram and bypass the switch if you wanted to. Rapidly flipping the switch up and down worked for me for several years, till that didn't work anymore. I then bypassed the wiring in the switch, since I was only running one tank also.
Thread
Thread Starter
Forum
Replies
Last Post