Hey all, I have a 1995 F-250 7.3 with dual tanks. When I filled up my front tank (back tank was at about 1/4) a few nights ago I noticed that my gauge would stick between half and 3/4 tank. Well I went on a trip and my fuel gauge started going down after about 60 miles of driving (at about the point to where it would be after driving that distance) and from there it started to go down at a normal rate. Yesterday I filled up my front and back tank to the point where it over flowed. The needle was still stuck at the same spot. I switched it the back tank and it didn't change, still at the 5/8th mark. Once I burned 3/8ths tank it would start working like nothing even happened.

If you all have any ideas what to do any help would be appreciated!! Thank you.

 

Check the grounds going to the fuel tanks. That can cause funny fuel guage readings.

To me, it looks like the gauge itself is sticking as both tanks show the same problem. Lightly tap the cluster and see if the needle unsticks or pull off the cluster's plastic lens and wiggle the needle.

 

It is normal for the needle to say passed full for a while. If it is not pased full then it sounds like the needle has slipped on its shaft.

 

It use to go over full but now it wont. I don't thing it slipped ob the shaft because it won't go under empty. I will check grounds when I get a chance to pull my truck in the shop. It will probably be Monday night.

 

Note a bad ground for the tank would cause the needle to peg beyond full. The tank ground is located on the drivers side radiator support (G100).
The cluster grounds are G200 & G201. You might also check the body ground G101.

Fuel tank ground G100:


Cluster ground G200:


Cluster ground G201:



Body ground G101:

 

Ok well I finally got back home again and I'm looking at the grounds. I got to the one on the passenger kick panel and now the back tank reads up to full by the front tank doesnt. Should I try all the rest?

 

I just started having a similar problem on my 1990 f250 with dual tanks. I just had the front fuel pump replaced and the gauge worked fine for the first tankful. I switched and ran on the rear and then went to fill up both tanks. Now the front ran down to about 1/4 tank, and I filled it back to full. Now the gauge stays right around the 1/4 tank mark. There have been a couple times driving down the road that it will start going back up towards full but it almost immediately stops and falls back and rests at the 1/4 mark.

If I switch to the rear tank it reads normally.

I thought maybe the float was junk since I just had the whole fuel pump / sending unit replaced, but since it will randomly start going up and then fall back I tend to lean toward it being a bad ground as mentioned before?

Am I off on this?

I will be checking those grounds as soon as I can.

 

No the grounds would have nothing to do with it. With a bad ground the fuel gauge would read full or above.

More than likely you have a bad connection on top of the tank where the wiring plugs into the top of the fuel hanger.