Fuel gauge reading wrong (1 Viewer)

[MadMace]

My fuel gauge is reading wrong—it is 1/2 off. In other words, when I have a full tank the gauge reads 1/2 full and so on as the fuel level drops.

I’ve searched through the previous threads and they mainly reference gauges that are not working at all. Mine works, it’s just not reading right.

Here is what I’ve done, I’ve followed the procedures outlined in the FSM.

1. Pulled the sender from the tank. It is very clean. Tested the resistance at F, 1/2, and E float levels and readings were within spec. For good measure, I cleaned the terminals on the sander and cable.

2. Pulled the drivers side back panel card off to get to the wiring harness that the sender wire feeds into. My God was there a ton of dirt in there. There was at least an inch thick layer of dirt in the bottom of the back quarter panel. The Y-R wire was quite frayed so I repaired that, no change.

3. I tested the voltage to the gauge through the harness wires as per the FSM—gauge bounced around 3.5V.

4. I touched the 2 wires that go to the fuel gauge together (one is Y-R and one is BR) and it move the fuel gauge needle above the F on the gauge which, from what I read, means the gauge is working.

I cannot find where the ground attaches To the frame. I have seen some threads that say it attaches to the flange of the gas tank but cannot find where it is to clean it off.

What am I missing here? Is it that my fuel gauge is faulty and needs to be replaced. How often do fuel gauges go bad?

Any help on what I should do next is greatly appreciated.

BTW, yes, I know I can set the odometer each time I fuel up to know when I need to refuel. But, I have terrible OCD and am very stubborn so I am dead set on getting this gauge to read right.

 

[g-man]

There is a blue wire connector in the driver's side quarter panel under the jack. Make sure this is not corroded. The sender wire goes thru this connector. When my fuel gauge stopped working this was the culprit.

 

[hobbadehoy]

Having a similar issue (mine reads 3/4 when actually full)

 

[MadMace]

There is a blue wire connector in the driver's side quarter panel under the jack. Make sure this is not corroded. The sender wire goes thru this connector. When my fuel gauge stopped working this was the culprit.

Yes, I found that connector. It took some effort but I was able to get it apart. I applied DeoxIT to both ends to get it good and clean as it was in there with all that dirt.

 

[OSS]

Pull the sender from the tank again and test it by moving the lever to Full while ignition is ON (not engine) and see if the needle on the gauge rises to full.

 

[MadMace]

Pull the sender from the tank again and test it by moving the lever to Full while ignition is ON (not engine) and see if the needle on the gauge rises to full.

When I pulled the sender for inspection, I did what you suggested. I put in the float in the "F" position (all the way up) and the needle went a little above 1/2 but not much. I also moved the float down to the "1/2" and "E" positions and the needle steadily moved down. When the float is at the "1/2" position is just at the top of the "E". When in the "E" position the needle pretty much bottoms out on the gauge.

 

[FishNinJay]

subscribed

 

[g-man]

Looking at the FSM you can measure resistance of the fuel gauge.

 

[MadMace]

Looking at the FSM you can measure resistance of the fuel gauge.

I think that is the next best step. I was hoping not to have to pull the cluster out but I think that needs to be done. I was hoping to be able to track the ground down so I could make sure it wasn't corroded.

When I get home tonight, I'm going to try that and I'll report back.

 

[MadMace]

Yahtzee!! @g-man looks like you’re right.

Looks like search for a new fuel gauge begins.


If somebody has a working on let me know.

 

[MadMace]

I suspect these small burn areas are the problem.

 

[g-man]

For Sale - 60 series gauge cluster

60 series gauge cluster minus the tach. Asking $50 obo Thanks, Joe

forum.ih8mud.com

 

[g-man]

this is a steal ^^^.

 

[MadMace]

this is a steal ^^^.

Yes, it sure is. I just sent him a PM to buy it. Again, thank you very much.

On a side note, interesting that the resistance reading I get is about 1/2 the resistance value listed as spec in the FSM.

 

[OSS]

The FJ62 fuel gauge is exactly the same as the FJ60 fuel gauge except it has a better dial. I put one in mine.
They're easier to find.

 

[MadMace]

The FJ62 fuel gauge is exactly the same as the FJ60 fuel gauge except it has a better dial. I put one in mine.
They're easier to find.

Great idea! Your temp gauge also looks different. Is it also from an FJ62?

 

[FJ60Seth]

Eliminate bad wiring as the problem. Remove the sender and the cluster. From the wiring diagram identify 12v switched, ground, and the 2 wires from sender. Using new wire, connect the sender to the gauge. Provide 12v and ground. Now move the sender and see what the gauge reads.

I replaced my cluster with Speed Hut gauges about a month ago. The gas gauge worked perfectly. PM me if you need it.

 

[MadMace]

Eliminate bad wiring as the problem. Remove the sender and the cluster. From the wiring diagram identify 12v switched, ground, and the 2 wires from sender. Using new wire, connect the sender to the gauge. Provide 12v and ground. Now move the sender and see what the gauge reads.

I replaced my cluster with Speed Hut gauges about a month ago. The gas gauge worked perfectly. PM me if you need it.

I think this is a great idea.

One of the things that I appreciate the most on the site (besides, of course, all the direct help and knowledge of others) is the ability to search for solutions to problems that arise. One of the most frustrating things is finding a thread where somebody has the same problem you do and it dead-ends with no solution being presented.

So, that being said, I’d like to make sure this thread presents a how-to that comes that shows others how to work through this to the end.

That is where I need a little help to make sure I don’t “f” anything up and give proper instruction to others in the future who find this thread.

Here are the wiring diagrams from the FSM for the gauge.

A couple of quick observations. Temp gauge is powered through the fuel gauge and shares a common ground with the high beam light. That is why temp gauge and fuel gauge problems can and often will occur at the same time.

Here is how the pins on the connector correspond to the posts on the back of the fuel gauge:

 

[MadMace]

@FJ60Seth has a great idea and one I’d like to do for my own knowledge and for posterity. The plan is to pull the sender and gauge. Attach the sender directly to the gauge as indicated in the picture below and attach 12V power source as shown. Then, move the float to the F, 1/2, and E positions to see how it affects the gauge reading.

Before I run the test, can people please chime in to confirm that I am attaching it correctly.

Y-R indicates where the yellow with red stripe wire and the BR is for the brown wire that attach to the sender.

 

[g-man]

# 3 pin is incoming voltage from the gauge fuse per the fsm diagram below...and according to your blue arrow ( and the circuit board in the back of the 4 gauge cluster) it shows this connected to the top right post on the back of the fuel sender. Would you have to run a jumper wire from the top right post to the gauge fuse?